bionic (1) duplicity.1.gz

Provided by: duplicity_0.7.17-0ubuntu1.1_amd64 bug

NAME

       duplicity - Encrypted incremental backup to local or remote storage.

SYNOPSIS

       For detailed descriptions for each command see chapter ACTIONS.

       duplicity [full|incremental] [options] source_directory target_url

       duplicity verify [options] [--compare-data] [--file-to-restore <relpath>] [--time time] source_url
       target_directory

       duplicity collection-status [options] target_url

       duplicity list-current-files [options] [--time time] target_url

       duplicity [restore] [options] [--file-to-restore <relpath>] [--time time] source_url target_directory

       duplicity remove-older-than <time> [options] [--force] target_url

       duplicity remove-all-but-n-full <count> [options] [--force] target_url

       duplicity remove-all-inc-of-but-n-full <count> [options] [--force] target_url

       duplicity cleanup [options] [--force] [--extra-clean] target_url

DESCRIPTION

       Duplicity incrementally backs up files and folders into tar-format volumes encrypted with GnuPG and
       places them to a remote (or local) storage backend.  See chapter URL FORMAT for a list of all supported
       backends and how to address them.  Because duplicity uses librsync, incremental backups are space
       efficient and only record the parts of files that have changed since the last backup.  Currently
       duplicity supports deleted files, full Unix permissions, uid/gid, directories, symbolic links, fifos,
       etc., but not hard links.

       If you are backing up the root directory /, remember to --exclude /proc, or else duplicity will probably
       crash on the weird stuff in there.

EXAMPLES

       Here is an example of a backup, using sftp to back up /home/me to some_dir on the other.host machine:

              duplicity /home/me sftp://uid@other.host/some_dir

       If the above is run repeatedly, the first will be a full backup, and subsequent ones will be incremental.
       To force a full backup, use the full action:

              duplicity full /home/me sftp://uid@other.host/some_dir

       or enforcing a full every other time via --full-if-older-than <time> , e.g. a full every month:

              duplicity --full-if-older-than 1M /home/me sftp://uid@other.host/some_dir

       Now suppose we accidentally delete /home/me and want to restore it the way it was at the time of last
       backup:

              duplicity sftp://uid@other.host/some_dir /home/me

       Duplicity enters restore mode because the URL comes before the local directory.  If we wanted to restore
       just the file "Mail/article" in /home/me as it was three days ago into /home/me/restored_file:

              duplicity -t 3D --file-to-restore Mail/article sftp://uid@other.host/some_dir
              /home/me/restored_file

       The following command compares the latest backup with the current files:

              duplicity verify sftp://uid@other.host/some_dir /home/me

       Finally, duplicity recognizes several include/exclude options.  For instance, the following will backup
       the root directory, but exclude /mnt, /tmp, and /proc:

              duplicity --exclude /mnt --exclude /tmp --exclude /proc / file:///usr/local/backup

       Note that in this case the destination is the local directory /usr/local/backup.  The following will
       backup only the /home and /etc directories under root:

              duplicity --include /home --include /etc --exclude '**' / file:///usr/local/backup

       Duplicity can also access a repository via ftp.  If a user name is given, the environment variable
       FTP_PASSWORD is read to determine the password:

              FTP_PASSWORD=mypassword duplicity /local/dir ftp://user@other.host/some_dir

ACTIONS

       Duplicity knows action commands, which can be finetuned with options.
       The actions for backup (full,incr) and restoration (restore) can as well be left out as duplicity detects
       in what mode it should switch to by the order of target URL and local folder. If the target URL comes
       before the local folder a restore is in order, is the local folder before target URL then this folder is
       about to be backed up to the target URL.
       If a backup is in order and old signatures can be found duplicity automatically performs an incremental
       backup.

       Note: The following explanations explain some but not all options that can be used in connection with
       that action command.  Consult the OPTIONS section for more detailed informations.

       full <folder> <url>
              Perform a full backup. A new backup chain is started even if signatures are available for an
              incremental backup.

       incr <folder> <url>
              If this is requested an incremental backup will be performed.  Duplicity will abort if no old
              signatures can be found.

       verify [--compare-data] [--time <time>] [--file-to-restore <rel_path>] <url> <local_path>
              Restore backup contents temporarily file by file and compare against the local path's contents.
              duplicity will exit with a non-zero error level if any files are different.  On verbosity level
              info (4) or higher, a message for each file that has changed will be logged.
              The --file-to-restore option restricts verify to that file or folder.  The --time option allows to
              select a backup to verify against.  The --compare-data option enables data comparison (see below).

       collection-status <url>
              Summarize the status of the backup repository by printing the chains and sets found, and the
              number of volumes in each.

       list-current-files [--time <time>] <url>
              Lists the files contained in the most current backup or backup at time.  The information will be
              extracted from the signature files, not the archive data itself. Thus the whole archive does not
              have to be downloaded, but on the other hand if the archive has been deleted or corrupted, this
              command will not detect it.

       restore [--file-to-restore <relpath>] [--time <time>] <url> <target_folder>
              You can restore the full monty or selected folders/files from a specific time.  Use the relative
              path as it is printed by list-current-files.  Usually not needed as duplicity enters restore mode
              when it detects that the URL comes before the local folder.

       remove-older-than <time> [--force] <url>
              Delete all backup sets older than the given time.  Old backup sets will not be deleted if backup
              sets newer than time depend on them.  See the TIME FORMATS section for more information.  Note,
              this action cannot be combined with backup or other actions, such as cleanup.  Note also that
              --force will be needed to delete the files instead of just listing them.

       remove-all-but-n-full <count> [--force] <url>
              Delete all backups sets that are older than the count:th last full backup (in other words, keep
              the last count full backups and associated incremental sets).  count must be larger than zero. A
              value of 1 means that only the single most recent backup chain will be kept.  Note that --force
              will be needed to delete the files instead of just listing them.

       remove-all-inc-of-but-n-full <count> [--force] <url>
              Delete incremental sets of all backups sets that are older than the count:th last full backup (in
              other words, keep only old full backups and not their increments).  count must be larger than
              zero. A value of 1 means that only the single most recent backup chain will be kept intact.  Note
              that --force will be needed to delete the files instead of just listing them.

       cleanup [--force] [--extra-clean] <url>
              Delete the extraneous duplicity files on the given backend.  Non-duplicity files, or files in
              complete data sets will not be deleted.  This should only be necessary after a duplicity session
              fails or is aborted prematurely.  Note that --force will be needed to delete the files instead of
              just listing them.

OPTIONS

       --allow-source-mismatch
              Do not abort on attempts to use the same archive dir or remote backend to back up different
              directories. duplicity will tell you if you need this switch.

       --archive-dir path
              The archive directory.  NOTE: This option changed in 0.6.0.  The archive directory is now
              necessary in order to manage persistence for current and future enhancements.  As such, this
              option is now used only to change the location of the archive directory.  The archive directory
              should not be deleted, or duplicity will have to recreate it from the remote repository (which may
              require decrypting the backup contents).

              When backing up or restoring, this option specifies that the local archive directory is to be
              created in path.  If the archive directory is not specified, the default will be to create the
              archive directory in ~/.cache/duplicity/.

              The archive directory can be shared between backups to multiple targets, because a subdirectory of
              the archive dir is used for individual backups (see --name ).

              The combination of archive directory and backup name must be unique in order to separate the data
              of different backups.

              The interaction between the --archive-dir and the --name options allows for four possible
              combinations for the location of the archive dir:

              1.     neither specified (default)
                      ~/.cache/duplicity/hash-of-url

              2.     --archive-dir=/arch, no --name
                      /arch/hash-of-url

              3.     no --archive-dir, --name=foo
                      ~/.cache/duplicity/foo

              4.     --archive-dir=/arch, --name=foo
                      /arch/foo

       --asynchronous-upload
              (EXPERIMENTAL) Perform file uploads asynchronously in the background, with respect to volume
              creation. This means that duplicity can upload a volume while, at the same time, preparing the
              next volume for upload. The intended end-result is a faster backup, because the local CPU and your
              bandwidth can be more consistently utilized. Use of this option implies additional need for disk
              space in the temporary storage location; rather than needing to store only one volume at a time,
              enough storage space is required to store two volumes.

       --backend-retry-delay number
              Specifies the number of seconds that duplicity waits after an error has occured before attempting
              to repeat the operation.

       --cf-backend backend
              Allows the explicit selection of a cloudfiles backend. Defaults to pyrax.  Alternatively you might
              choose cloudfiles.

       --compare-data
              Enable data comparison of regular files on action verify.  This is disabled by default for
              performance reasons.

       --copy-links
              Resolve symlinks during backup.  Enabling this will resolve & back up the symlink's file/folder
              data instead of the symlink itself, potentially increasing the size of the backup.

       --dry-run
              Calculate what would be done, but do not perform any backend actions

       --encrypt-key key-id
              When backing up, encrypt to the given public key, instead of using symmetric (traditional)
              encryption.  Can be specified multiple times.  The key-id can be given in any of the formats
              supported by GnuPG; see gpg(1), section "HOW TO SPECIFY A USER ID" for details.

       --encrypt-secret-keyring filename
              This option can only be used with --encrypt-key, and changes the path to the secret keyring for
              the encrypt key to filename This keyring is not used when creating a backup. If not specified, the
              default secret keyring is used which is usually located at .gnupg/secring.gpg

       --encrypt-sign-key key-id
              Convenience parameter. Same as --encrypt-key key-id --sign-key key-id.

       --exclude shell_pattern
              Exclude the file or files matched by shell_pattern.  If a directory is matched, then files under
              that directory will also be matched.  See the FILE SELECTION section for more information.

       --exclude-device-files
              Exclude all device files.  This can be useful for security/permissions reasons or if rdiff-backup
              is not handling device files correctly.

       --exclude-filelist filename
              Excludes the files listed in filename, with each line of the filelist interpreted according to the
              same rules as --include and --exclude.  See the FILE SELECTION section for more information.

       --exclude-if-present filename
              Exclude directories if filename is present. Allows the user to specify folders that they do not
              wish to backup by adding a specified file (e.g. ".nobackup") instead of maintaining a
              comprehensive exclude/include list. This option needs to come before any other include or exclude
              options.

       --exclude-older-than time
              Exclude any files whose modification date is earlier than the specified time.  This can be used to
              produce a partial backup that contains only recently changed files. See the TIME FORMATS section
              for more information.

       --exclude-other-filesystems
              Exclude files on file systems (identified by device number) other than the file system the root of
              the source directory is on.

       --exclude-regexp regexp
              Exclude files matching the given regexp.  Unlike the --exclude option, this option does not match
              files in a directory it matches.  See the FILE SELECTION section for more information.

       --extra-clean
              When cleaning up, be more aggressive about saving space.  For example, this may delete signature
              files for old backup chains.

              Caution: Without signature files those old backup chains are unrestorable. Do not use --extra-
              clean unless you know what you're doing.

              See the cleanup argument for more information.

       --file-prefix, --file-prefix-manifest, --file-prefix-archive, --file-prefix-signature
              Adds a prefix to all files, manifest files, archive files, and/or signature files.

              The same set of prefixes must be passed in on backup and restore.

              If both global and type-specific prefixes are set, global prefix will go before type-specific
              prefixes.

              See also A NOTE ON FILENAME PREFIXES

       --file-to-restore path
              This option may be given in restore mode, causing only path to be restored instead of the entire
              contents of the backup archive.  path should be given relative to the root of the directory backed
              up.

       --full-if-older-than time
              Perform a full backup if an incremental backup is requested, but the latest full backup in the
              collection is older than the given time.  See the TIME FORMATS section for more information.

       --force
              Proceed even if data loss might result.  Duplicity will let the user know when this option is
              required.

       --ftp-passive
              Use passive (PASV) data connections.  The default is to use passive, but to fallback to regular if
              the passive connection fails or times out.

       --ftp-regular
              Use regular (PORT) data connections.

       --gio  Use the GIO backend and interpret any URLs as GIO would.

       --hidden-encrypt-key key-id
              Same as --encrypt-key, but it hides user's key id from encrypted file. It uses the gpg's --hidden-
              recipient command to obfuscate the owner of the backup. On restore, gpg will automatically try all
              available secret keys in order to decrypt the backup. See gpg(1) for more details.

       --ignore-errors
              Try to ignore certain errors if they happen. This option is only intended to allow the restoration
              of a backup in the face of certain problems that would otherwise cause the backup to fail. It is
              not ever recommended to use this option unless you have a situation where you are trying to
              restore from backup and it is failing because of an issue which you want duplicity to ignore. Even
              then, depending on the issue, this option may not have an effect.

              Please note that while ignored errors will be logged, there will be no summary at the end of the
              operation to tell you what was ignored, if anything. If this is used for emergency restoration of
              data, it is recommended that you run the backup in such a way that you can revisit the backup log
              (look for lines containing the string IGNORED_ERROR).

              If you ever have to use this option for reasons that are not understood or understood but not your
              own responsibility, please contact duplicity maintainers. The need to use this option under
              production circumstances would normally be considered a bug.

       --imap-full-address email_address
              The full email address of the user name when logging into an imap server.  If not supplied just
              the user name part of the email address is used.

       --imap-mailbox option
              Allows you to specify a different mailbox.  The default is "INBOX".  Other languages may require a
              different mailbox than the default.

       --gpg-binary file_path
              Allows you to force duplicity to use file_path as gpg command line binary. Can be an absolute or
              relative file path or a file name.  Default value is 'gpg'. The binary will be localized via the
              PATH environment variable.

       --gpg-options options
              Allows you to pass options to gpg encryption.  The options list should be of the form "--opt1
              --opt2=parm" where the string is quoted and the only spaces allowed are between options.

       --include shell_pattern
              Similar to --exclude but include matched files instead.  Unlike --exclude, this option will also
              match parent directories of matched files (although not necessarily their contents).  See the FILE
              SELECTION section for more information.

       --include-filelist filename
              Like --exclude-filelist, but include the listed files instead.  See the FILE SELECTION section for
              more information.

       --include-regexp regexp
              Include files matching the regular expression regexp.  Only files explicitly matched by regexp
              will be included by this option.  See the FILE SELECTION section for more information.

       --log-fd number
              Write specially-formatted versions of output messages to the specified file descriptor.  The
              format used is designed to be easily consumable by other programs.

       --log-file filename
              Write specially-formatted versions of output messages to the specified file.  The format used is
              designed to be easily consumable by other programs.

       --max-blocksize number
              determines the number of the blocks examined for changes during the diff process.  For files < 1MB
              the blocksize is a constant of 512.  For files over 1MB the size is given by:

              file_blocksize = int((file_len / (2000 * 512)) * 512)
              return min(file_blocksize, globals.max_blocksize)

              where globals.max_blocksize defaults to 2048.  If you specify a larger max_blocksize, your difftar
              files will be larger, but your sigtar files will be smaller.  If you specify a smaller
              max_blocksize, the reverse occurs.  The --max-blocksize option should be in multiples of 512.

       --name symbolicname
              Set the symbolic name of the backup being operated on. The intent is to use a separate name for
              each logically distinct backup. For example, someone may use "home_daily_s3" for the daily backup
              of a home directory to Amazon S3. The structure of the name is up to the user, it is only
              important that the names be distinct. The symbolic name is currently only used to affect the
              expansion of --archive-dir , but may be used for additional features in the future. Users running
              more than one distinct backup are encouraged to use this option.

              If not specified, the default value is a hash of the backend URL.

       --no-compression
              Do not use GZip to compress files on remote system.

       --no-encryption
              Do not use GnuPG to encrypt files on remote system.

       --no-print-statistics
              By default duplicity will print statistics about the current session after a successful backup.
              This switch disables that behavior.

       --null-separator
              Use nulls (\0) instead of newlines (\n) as line separators, which may help when dealing with
              filenames containing newlines.  This affects the expected format of the files specified by the
              --{include|exclude}-filelist switches as well as the format of the directory statistics file.

       --numeric-owner
              On restore always use the numeric uid/gid from the archive and not the archived user/group names,
              which is the default behaviour.  Recommended for restoring from live cds which might have the
              users with identical names but different uids/gids.

       --num-retries number
              Number of retries to make on errors before giving up.

       --old-filenames
              Use the old filename format (incompatible with Windows/Samba) rather than the new filename format.

       --par2-options options
              Verbatim options to pass to par2.

       --par2-redundancy percent
              Adjust the level of redundancy in percent for Par2 recovery files (default 10%).

       --progress
              When selected, duplicity will output the current upload progress and estimated upload time. To
              annotate changes, it will perform a first dry-run before a full or incremental, and then runs the
              real operation estimating the real upload progress.

       --progress-rate number
              Sets the update rate at which duplicity will output the upload progress messages (requires
              --progress option). Default is to prompt the status each 3 seconds.

       --rename <original path> <new path>
              Treats the path orig in the backup as if it were the path new.  Can be passed multiple times. An
              example:

              duplicity restore --rename Documents/metal Music/metal sftp://uid@other.host/some_dir /home/me

       --rsync-options options
              Allows you to pass options to the rsync backend.  The options list should be of the form
              "opt1=parm1 opt2=parm2" where the option string is quoted and the only spaces allowed are between
              options. The option string will be passed verbatim to rsync, after any internally generated option
              designating the remote port to use. Here is a possibly useful example:

              duplicity --rsync-options="--partial-dir=.rsync-partial" /home/me rsync://uid@other.host/some_dir

       --s3-european-buckets
              When using the Amazon S3 backend, create buckets in Europe instead of the default (requires
              --s3-use-new-style ). Also see the EUROPEAN S3 BUCKETS section.

       --s3-unencrypted-connection
              Don't use SSL for connections to S3.

              This may be much faster, at some cost to confidentiality.

              With this option, anyone who can observe traffic between your computer and S3 will be able to
              tell: that you are using Duplicity, the name of the bucket, your AWS Access Key ID, the increment
              dates and the amount of data in each increment.

              This option affects only the connection, not the GPG encryption of the backup increment files.
              Unless that is disabled, an observer will not be able to see the file names or contents.

       --s3-use-new-style
              When operating on Amazon S3 buckets, use new-style subdomain bucket addressing. This is now the
              preferred method to access Amazon S3, but is not backwards compatible if your bucket name contains
              upper-case characters or other characters that are not valid in a hostname.

       --s3-use-rrs
              Store volumes using Reduced Redundancy Storage when uploading to Amazon S3.  This will lower the
              cost of storage but also lower the durability of stored volumes to 99.99% instead the
              99.999999999% durability offered by Standard Storage on S3.

       --s3-use-ia
              Store volumes using Standard - Infrequent Access when uploading to Amazon S3.  This storage class
              has a lower storage cost but a higher per-request cost, and the storage cost is calculated against
              a 30-day storage minimum. According to Amazon, this storage is ideal for long-term file storage,
              backups, and disaster recovery.

       --s3-use-multiprocessing
              Allow multipart volumne uploads to S3 through multiprocessing. This option requires Python 2.6 and
              can be used to make uploads to S3 more efficient.  If enabled, files duplicity uploads to S3 will
              be split into chunks and uploaded in parallel. Useful if you want to saturate your bandwidth or if
              large files are failing during upload.

       --s3-use-server-side-encryption
              Allow use of server side encryption in S3

       --s3-multipart-chunk-size
              Chunk size (in MB) used for S3 multipart uploads. Make this smaller than --volsize to maximize the
              use of your bandwidth. For example, a chunk size of 10MB with a volsize of 30MB will result in 3
              chunks per volume upload.

       --s3-multipart-max-procs
              Specify the maximum number of processes to spawn when performing a multipart upload to S3. By
              default, this will choose the number of processors detected on your system (e.g. 4 for a 4-core
              system). You can adjust this number as required to ensure you don't overload your system while
              maximizing the use of your bandwidth.

       --s3-multipart-max-timeout
              You can control the maximum time (in seconds) a multipart upload can spend on uploading a single
              chunk to S3. This may be useful if you find your system hanging on multipart uploads or if you'd
              like to control the time variance when uploading to S3 to ensure you kill connections to slow S3
              endpoints.

       --scp-command command
              (only ssh pexpect backend with --use-scp enabled) The command will be used instead of "scp" to
              send or receive files.  To list and delete existing files, the sftp command is used.
              See also A NOTE ON SSH BACKENDS section SSH pexpect backend.

       --sftp-command command
              (only ssh pexpect backend) The command will be used instead of "sftp".
              See also A NOTE ON SSH BACKENDS section SSH pexpect backend.

       --short-filenames
              If this option is specified, the names of the files duplicity writes will be shorter (about 30
              chars) but less understandable.  This may be useful when backing up to MacOS or another OS or FS
              that doesn't support long filenames.

       --sign-key key-id
              This option can be used when backing up, restoring or verifying.  When backing up, all backup
              files will be signed with keyid key.  When restoring, duplicity will signal an error if any remote
              file is not signed with the given key-id. The key-id can be given in any of the formats supported
              by GnuPG; see gpg(1), section "HOW TO SPECIFY A USER ID" for details.  Should be specified only
              once because currently only one signing key is supported. Last entry overrides all other entries.
              See also A NOTE ON SYMMETRIC ENCRYPTION AND SIGNING

       --ssh-askpass
              Tells the ssh backend to prompt the user for the remote system password, if it was not defined in
              target url and no FTP_PASSWORD env var is set.  This password is also used for passphrase-
              protected ssh keys.

       --ssh-options options
              Allows you to pass options to the ssh backend.  Can be specified multiple times or as a space
              separated options list.  The options list should be of the form "-oOpt1='parm1' -oOpt2='parm2'"
              where the option string is quoted and the only spaces allowed are between options. The option
              string will be passed verbatim to both scp and sftp, whose command line syntax differs slightly
              hence the options should therefore be given in the long option format described in ssh_config(5).

              example of a list:

              duplicity --ssh-options="-oProtocol=2 -oIdentityFile='/my/backup/id'" /home/me
              scp://user@host/some_dir

              example with multiple parameters:

              duplicity --ssh-options="-oProtocol=2" --ssh-options="-oIdentityFile='/my/backup/id'" /home/me
              scp://user@host/some_dir

              NOTE: The ssh paramiko backend currently supports only the -i or -oIdentityFile setting. If needed
              provide more host specific options via ssh_config file.

       --ssl-cacert-file file
              (only webdav & lftp backend) Provide a cacert file for ssl certificate verification.
              See also A NOTE ON SSL CERTIFICATE VERIFICATION.

       --ssl-cacert-path path/to/certs/
              (only webdav backend and python 2.7.9+ OR lftp+webdavs and a recent lftp) Provide a path to a
              folder containing cacert files for ssl certificate verification.
              See also A NOTE ON SSL CERTIFICATE VERIFICATION.

       --ssl-no-check-certificate
              (only webdav & lftp backend) Disable ssl certificate verification.
              See also A NOTE ON SSL CERTIFICATE VERIFICATION.

       --tempdir directory
              Use this existing directory for duplicity temporary files instead of the system default, which is
              usually the /tmp directory. This option supersedes any environment variable.
              See also ENVIRONMENT VARIABLES.

       -ttime, --time time, --restore-time time
              Specify the time from which to restore or list files.

       --time-separator char
              Use char as the time separator in filenames instead of colon (":").

       --timeout seconds
              Use seconds as the socket timeout value if duplicity begins to timeout during network operations.
              The default is 30 seconds.

       --use-agent
              If this option is specified, then --use-agent is passed to the GnuPG encryption process and it
              will try to connect to gpg-agent before it asks for a passphrase for --encrypt-key or --sign-key
              if needed.
              Note: Contrary to previous versions of duplicity, this option will also be honored by GnuPG 2 and
              newer versions. If GnuPG 2 is in use, duplicity passes the option --pinentry-mode=loopback to the
              the gpg process unless --use-agent is specified on the duplicity command line. This has the effect
              that GnuPG 2 uses the agent only if --use-agent is given, just like GnuPG 1.

       --verbosity level, -vlevel
              Specify output verbosity level (log level).  Named levels and corresponding values are 0 Error, 2
              Warning, 4 Notice (default), 8 Info, 9 Debug (noisiest).
              level may also be
              a character: e, w, n, i, d
              a word: error, warning, notice, info, debug

              The options -v4, -vn and -vnotice are functionally equivalent, as are the mixed/upper-case
              versions -vN, -vNotice and -vNOTICE.

       --version
              Print duplicity's version and quit.

       --volsize number
              Change the volume size to number MB. Default is 200MB.

ENVIRONMENT VARIABLES

       TMPDIR, TEMP, TMP
              In decreasing order of importance, specifies the directory to use for temporary files (inherited
              from Python's tempfile module).  Eventually the option --tempdir supercedes any of these.

       FTP_PASSWORD
              Supported by most backends which are password capable. More secure than setting it in the backend
              url (which might be readable in the operating systems process listing to other users on the same
              machine).

       PASSPHRASE
              This passphrase is passed to GnuPG. If this is not set, the user will be prompted for the
              passphrase.

       SIGN_PASSPHRASE
              The passphrase to be used for --sign-key.  If ommitted and sign key is also one of the keys to
              encrypt against PASSPHRASE will be reused instead.  Otherwise, if passphrase is needed but not set
              the user will be prompted for it.

URL FORMAT

       Duplicity uses the URL format (as standard as possible) to define data locations.  The generic format for
       a URL is:

              scheme://[user[:password]@]host[:port]/[/]path

       It is not recommended to expose the password on the command line since it could be revealed to anyone
       with permissions to do process listings, it is permitted however.  Consider setting the environment
       variable FTP_PASSWORD instead, which is used by most, if not all backends, regardless of it's name.

       In protocols that support it, the path may be preceded by a single slash, '/path', to represent a
       relative path to the target home directory, or preceded by a double slash, '//path', to represent an
       absolute filesystem path.

       Note:
              Scheme (protocol) access may be provided by more than one backend.  In case the default backend is
              buggy or simply not working in a specific case it might be worth trying an alternative
              implementation.  Alternative backends can be selected by prefixing the scheme with the name of the
              alternative backend e.g.  ncftp+ftp:// and are mentioned below the scheme's syntax summary.

       Formats of each of the URL schemes follow:

       Azure

              azure://container-name

              See also A NOTE ON AZURE ACCESS

       B2

              b2://account_id[:application_key]@bucket_name/[folder/]

       Cloud Files (Rackspace)

              cf+http://container_name

              See also A NOTE ON CLOUD FILES ACCESS

       Copy cloud storage

              copy://user[:password]@copy.com/some_dir

       Dropbox

              dpbx:///some_dir

              Make sure to read A NOTE ON DROPBOX ACCESS first!

       Local file path

              file://[relative|/absolute]/local/path

       FISH (Files transferred over Shell protocol) over ssh

              fish://user[:pwd]@other.host[:port]/[relative|/absolute]_path

       FTP

              ftp[s]://user[:password]@other.host[:port]/some_dir

              NOTE: use lftp+, ncftp+ prefixes to enforce a specific backend, default is lftp+ftp://...

       Google Docs

              gdocs://user[:password]@other.host/some_dir

              NOTE: use pydrive+, gdata+ prefixes to enforce a specific backend, default is pydrive+gdocs://...

       Google Cloud Storage

              gs://bucket[/prefix]

       HSI

              hsi://user[:password]@other.host/some_dir

       hubiC

              cf+hubic://container_name

              See also A NOTE ON HUBIC

       IMAP email storage

              imap[s]://user[:password]@host.com[/from_address_prefix]

              See also A NOTE ON IMAP

       Mega cloud storage

              mega://user[:password]@mega.co.nz/some_dir

       OneDrive Backend

              onedrive://some_dir

       Par2 Wrapper Backend

              par2+scheme://[user[:password]@]host[:port]/[/]path

              See also A NOTE ON PAR2 WRAPPER BACKEND

       Rsync via daemon

              rsync://user[:password]@host.com[:port]::[/]module/some_dir

       Rsync over ssh (only key auth)

              rsync://user@host.com[:port]/[relative|/absolute]_path

       S3 storage (Amazon)

              s3://host[:port]/bucket_name[/prefix]
              s3+http://bucket_name[/prefix]

              See also A NOTE ON EUROPEAN S3 BUCKETS

       SCP/SFTP access

              scp://.. or
              sftp://user[:pwd]@other.host[:port]/[relative|/absolute]_path

              defaults are paramiko+scp:// and paramiko+sftp://
              alternatively try pexpect+scp://, pexpect+sftp://, lftp+sftp://
              See also --ssh-askpass, --ssh-options and A NOTE ON SSH BACKENDS.

       Swift (Openstack)

              swift://container_name[/prefix]

              See also A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS

       Tahoe-LAFS

              tahoe://alias/directory

       WebDAV

              webdav[s]://user[:password]@other.host[:port]/some_dir

              alternatively try lftp+webdav[s]://

       pydrive

              pydrive://<service account' email address>@developer.gserviceaccount.com/some_dir

              See also A NOTE ON PYDRIVE BACKEND below.

       multi

              multi:///path/to/config.json

              See also A NOTE ON MULTI BACKEND below.

       MediaFire

              mf://user[:password]@mediafire.com/some_dir

              See also A NOTE ON MEDIAFIRE BACKEND below.

TIME FORMATS

       duplicity uses time strings in two places.  Firstly, many of the files duplicity creates will have the
       time in their filenames in the w3 datetime format as described in a w3 note at http://www.w3.org/TR/NOTE-
       datetime.  Basically they look like "2001-07-15T04:09:38-07:00", which means what it looks like.  The
       "-07:00" section means the time zone is 7 hours behind UTC.

       Secondly, the -t, --time, and --restore-time options take a time string, which can be given in any of
       several formats:

       1.     the string "now" (refers to the current time)

       2.     a sequences of digits, like "123456890" (indicating the time in seconds after the epoch)

       3.     A string like "2002-01-25T07:00:00+02:00" in datetime format

       4.     An interval, which is a number followed by one of the characters s, m, h, D, W, M, or Y
              (indicating seconds, minutes, hours, days, weeks, months, or years respectively), or a series of
              such pairs.  In this case the string refers to the time that preceded the current time by the
              length of the interval.  For instance, "1h78m" indicates the time that was one hour and 78 minutes
              ago.  The calendar here is unsophisticated: a month is always 30 days, a year is always 365 days,
              and a day is always 86400 seconds.

       5.     A date format of the form YYYY/MM/DD, YYYY-MM-DD, MM/DD/YYYY, or MM-DD-YYYY, which indicates
              midnight on the day in question, relative to the current time zone settings.  For instance,
              "2002/3/5", "03-05-2002", and "2002-3-05" all mean March 5th, 2002.

FILE SELECTION

       When duplicity is run, it searches through the given source directory and backs up all the files
       specified by the file selection system.  The file selection system comprises a number of file selection
       conditions, which are set using one of the following command line options:
              --exclude
              --exclude-device-files
              --exclude-filelist
              --exclude-regexp
              --include
              --include-filelist
              --include-regexp
       Each file selection condition either matches or doesn't match a given file.  A given file is excluded by
       the file selection system exactly when the first matching file selection condition specifies that the
       file be excluded; otherwise the file is included.

       For instance,

              duplicity --include /usr --exclude /usr /usr scp://user@host/backup

       is exactly the same as

              duplicity /usr scp://user@host/backup

       because the include and exclude directives match exactly the same files, and the --include comes first,
       giving it precedence.  Similarly,

              duplicity --include /usr/local/bin --exclude /usr/local /usr scp://user@host/backup

       would backup the /usr/local/bin directory (and its contents), but not /usr/local/doc.

       The include, exclude, include-filelist, and exclude-filelist options accept some extended shell globbing
       patterns.  These patterns can contain *, **, ?, and [...]  (character ranges). As in a normal shell, *
       can be expanded to any string of characters not containing "/", ?  expands to any character except "/",
       and [...]  expands to a single character of those characters specified (ranges are acceptable).  The new
       special pattern, **, expands to any string of characters whether or not it contains "/".  Furthermore, if
       the pattern starts with "ignorecase:" (case insensitive), then this prefix will be removed and any
       character in the string can be replaced with an upper- or lowercase version of itself.

       Remember that you may need to quote these characters when typing them into a shell, so the shell does not
       interpret the globbing patterns before duplicity sees them.

       The --exclude pattern option matches a file if:

       1.  pattern can be expanded into the file's filename, or
       2.  the file is inside a directory matched by the option.

       Conversely, the --include pattern matches a file if:

       1.  pattern can be expanded into the file's filename, or
       2.  the file is inside a directory matched by the option, or
       3.  the file is a directory which contains a file matched by the option.

       For example,

              --exclude /usr/local

       matches e.g. /usr/local, /usr/local/lib, and /usr/local/lib/netscape.  It is the same as --exclude
       /usr/local --exclude '/usr/local/**'.

       On the other hand

              --include /usr/local

       specifies that /usr, /usr/local, /usr/local/lib, and /usr/local/lib/netscape (but not /usr/doc) all be
       backed up. Thus you don't have to worry about including parent directories to make sure that included
       subdirectories have somewhere to go.

       Finally,

              --include ignorecase:'/usr/[a-z0-9]foo/*/**.py'

       would match a file like /usR/5fOO/hello/there/world.py.  If it did match anything, it would also match
       /usr.  If there is no existing file that the given pattern can be expanded into, the option will not
       match /usr alone.

       The --include-filelist, and --exclude-filelist, options also introduce file selection conditions.  They
       direct duplicity to read in a file, each line of which is a file specification, and to include or exclude
       the matching files.  Lines are separated by newlines or nulls, depending on whether the --null-separator
       switch was given.  Each line in the filelist will be interpreted as a globbing pattern the way --include
       and --exclude options are interpreted, except that lines starting with "+ " are interpreted as include
       directives, even if found in a filelist referenced by --exclude-filelist.  Similarly, lines starting with
       "- " exclude files even if they are found within an include filelist.

       For example, if file "list.txt" contains the lines:

              /usr/local
              - /usr/local/doc
              /usr/local/bin
              + /var
              - /var

       then --include-filelist list.txt would include /usr, /usr/local, and /usr/local/bin.  It would exclude
       /usr/local/doc, /usr/local/doc/python, etc.  It would also include /usr/local/man, as this is included
       within /user/local.  Finally, it is undefined what happens with /var.  A single file list should not
       contain conflicting file specifications.

       Each line in the filelist will also be interpreted as a globbing pattern the way --include and --exclude
       options are interpreted.  For instance, if the file "list.txt" contains the lines:

              dir/foo
              + dir/bar
              - **

       Then --include-filelist list.txt would be exactly the same as specifying --include dir/foo --include
       dir/bar --exclude ** on the command line.

       Finally, the --include-regexp and --exclude-regexp options allow files to be included and excluded if
       their filenames match a python regular expression.  Regular expression syntax is too complicated to
       explain here, but is covered in Python's library reference.  Unlike the --include and --exclude options,
       the regular expression options don't match files containing or contained in matched files.  So for
       instance

              --include '[0-9]{7}(?!foo)'

       matches any files whose full pathnames contain 7 consecutive digits which aren't followed by 'foo'.
       However, it wouldn't match /home even if /home/ben/1234567 existed.

A NOTE ON AZURE ACCESS

       The Azure backend requires the Microsoft Azure Storage SDK for Python to be installed on the system.  See
       REQUIREMENTS above.

       It uses two environment variables for authentification: AZURE_ACCOUNT_NAME (required), AZURE_ACCOUNT_KEY
       (required)

       A container name must be a valid DNS name, conforming to the following naming rules:

              1.     Container names must start with a letter or number, and can contain only letters, numbers,
                     and the dash (-) character.

              2.     Every dash (-) character must be immediately preceded and followed by a letter or number;
                     consecutive dashes are not permitted in container names.

              3.     All letters in a container name must be lowercase.

              4.     Container names must be from 3 through 63 characters long.

A NOTE ON CLOUD FILES ACCESS

       Pyrax is Rackspace's next-generation Cloud management API, including Cloud Files access.  The cfpyrax
       backend requires the pyrax library to be installed on the system.  See REQUIREMENTS above.

       Cloudfiles is Rackspace's now deprecated implementation of OpenStack Object Storage protocol.  Users
       wishing to use Duplicity with Rackspace Cloud Files should migrate to the new Pyrax plugin to ensure
       support.

       The backend requires python-cloudfiles to be installed on the system.  See REQUIREMENTS above.

       It uses three environment variables for authentification: CLOUDFILES_USERNAME (required),
       CLOUDFILES_APIKEY (required), CLOUDFILES_AUTHURL (optional)

       If CLOUDFILES_AUTHURL is unspecified it will default to the value provided by python-cloudfiles, which
       points to rackspace, hence this value must be set in order to use other cloud files providers.

A NOTE ON DROPBOX ACCESS

       1.     First of all Dropbox backend requires valid authentication token. It should be passed via
              DPBX_ACCESS_TOKEN environment variable.
              To obtain it please create 'Dropbox API' application at:
              https://www.dropbox.com/developers/apps/create
              Then visit app settings and just use 'Generated access token' under OAuth2 section.
              Alternatively you can let duplicity generate access token itself. In such case temporary export
              DPBX_APP_KEY , DPBX_APP_SECRET using values from app settings page and run duplicity
              interactively.
              It will print the URL that you need to open in the browser to obtain OAuth2 token for the
              application. Just follow on-screen instructions and then put generated token to DPBX_ACCESS_TOKEN
              variable. Once done, feel free to unset DPBX_APP_KEY and DPBX_APP_SECRET

       2.     "some_dir" must already exist in the Dropbox folder. Depending on access token kind it may be:
                     Full Dropbox: path is absolute and starts from 'Dropbox' root folder.
                     App Folder: path is related to application folder. Dropbox client will show it in
                     ~/Dropbox/Apps/<app-name>

       3.     When using Dropbox for storage, be aware that all files, including the ones in the Apps folder,
              will be synced to all connected computers.  You may prefer to use a separate Dropbox account
              specially for the backups, and not connect any computers to that account. Alternatively you can
              configure selective sync on all computers to avoid syncing of backup files

A NOTE ON EUROPEAN S3 BUCKETS

       Amazon S3 provides the ability to choose the location of a bucket upon its creation. The purpose is to
       enable the user to choose a location which is better located network topologically relative to the user,
       because it may allow for faster data transfers.

       duplicity will create a new bucket the first time a bucket access is attempted. At this point, the bucket
       will be created in Europe if --s3-european-buckets was given. For reasons having to do with how the
       Amazon S3 service works, this also requires the use of the --s3-use-new-style option. This option turns
       on subdomain based bucket addressing in S3. The details are beyond the scope of this man page, but it is
       important to know that your bucket must not contain upper case letters or any other characters that are
       not valid parts of a hostname. Consequently, for reasons of backwards compatibility, use of subdomain
       based bucket addressing is not enabled by default.

       Note that you will need to use --s3-use-new-style for all operations on European buckets; not just upon
       initial creation.

       You only need to use --s3-european-buckets upon initial creation, but you may may use it at all times for
       consistency.

       Further note that when creating a new European bucket, it can take a while before the bucket is fully
       accessible. At the time of this writing it is unclear to what extent this is an expected feature of
       Amazon S3, but in practice you may experience timeouts, socket errors or HTTP errors when trying to
       upload files to your newly created bucket. Give it a few minutes and the bucket should function normally.

A NOTE ON FILENAME PREFIXES

       Filename prefixes can be used in conjunction with S3 lifecycle rules to transition archive files to
       Glacier, while keeping metadata (signature and manifest files) on S3.

       Duplicity does not require access to archive files except when restoring from backup.

A NOTE ON GOOGLE CLOUD STORAGE

       Support for Google Cloud Storage relies on its Interoperable Access, which must be enabled for your
       account.  Once enabled, you can generate Interoperable Storage Access Keys and pass them to duplicity via
       the GS_ACCESS_KEY_ID and GS_SECRET_ACCESS_KEY environment variables. Alternatively, you can run gsutil
       config -a to have the Google Cloud Storage utility populate the ~/.boto configuration file.

       Enable Interoperable Access: https://code.google.com/apis/console#:storage
       Create Access Keys: https://code.google.com/apis/console#:storage:legacy

A NOTE ON HUBIC

       The hubic backend requires the pyrax library to be installed on the system. See REQUIREMENTS above.  You
       will need to set your credentials for hubiC in a file called ~/.hubic_credentials, following this
       pattern:

              [hubic]
              email = your_email
              password = your_password
              client_id = api_client_id
              client_secret = api_secret_key
              redirect_uri = http://localhost/

A NOTE ON IMAP

       An IMAP account can be used as a target for the upload.  The userid may be specified and the password
       will be requested.

       The from_address_prefix may be specified (and probably should be). The text will be used as the "From"
       address in the IMAP server.  Then on a restore (or list) command the from_address_prefix will distinguish
       between different backups.

A NOTE ON MULTI BACKEND

       The multi backend allows duplicity to combine the storage available in more than one backend store (e.g.,
       you can store across a google drive account and a onedrive account to get effectively the combined
       storage available in both).  The URL path specifies a JSON formated config file containing a list of the
       backends it will use. The URL may also specify "query" parameters to configure overall behavior.  Each
       element of the list must have a "url" element, and may also contain an optional "description" and an
       optional "env" list of environment variables used to configure that backend.

   Query Parameters
       Query parameters come after the file URL in standard HTTP format for example:
              multi:///path/to/config.json?mode=mirror&onfail=abort
              multi:///path/to/config.json?mode=stripe&onfail=continue
              multi:///path/to/config.json?onfail=abort&mode=stripe
              multi:///path/to/config.json?onfail=abort
       Order does not matter, however unrecognized parameters are considered an error.

       mode=stripe
              This mode (the default) performs round-robin access to the list of backends. In this mode, all
              backends must be reliable as a loss of one means a loss of one of the archive files.

       mode=mirror
              This mode accesses backends as a RAID1-store, storing every file in every backend and reading
              files from the first-successful backend.  A loss of any backend should result in no failure. Note
              that backends added later will only get new files and may require a manual sync with one of the
              other operating ones.

       onfail=continue
              This setting (the default) continues all write operations in as best-effort. Any failure results
              in the next backend tried. Failure is reported only when all backends fail a given operation with
              the error result from the last failure.

       onfail=abort
              This setting considers any backend write failure as a terminating condition and reports the error.
              Data reading and listing operations are independent of this and will try with the next backend on
              failure.

   JSON File Example
              [
               {
                "description": "a comment about the backend"
                "url": "abackend://myuser@domain.com/backup",
                "env": [
                  {
                   "name" : "MYENV",
                   "value" : "xyz"
                  },
                  {
                   "name" : "FOO",
                   "value" : "bar"
                  }
                 ]
               },
               {
                "url": "file:///path/to/dir"
               }
              ]

A NOTE ON PAR2 WRAPPER BACKEND

       Par2 Wrapper Backend can be used in combination with all other backends to create recovery files. Just
       add par2+ before a regular scheme (e.g.  par2+ftp://user@host/dir or par2+s3+http://bucket_name ). This
       will create par2 recovery files for each archive and upload them all to the wrapped backend.

       Before restoring, archives will be verified. Corrupt archives will be repaired on the fly if there are
       enough recovery blocks available.

       Use --par2-redundancy percent to adjust the size (and redundancy) of recovery files in percent.

A NOTE ON PYDRIVE BACKEND

       The pydrive backend requires Python PyDrive package to be installed on the system. See REQUIREMENTS
       above.

       There are two ways to use PyDrive: with a regular account or with a "service account". With a service
       account, a separate account is created, that is only accessible with Google APIs and not a web login.
       With a regular account, you can store backups in your normal Google Drive.

       To use a service account, go to the Google developers console at https://console.developers.google.com.
       Create a project, and make sure Drive API is enabled for the project. Under "APIs and auth", click Create
       New Client ID, then select Service Account with P12 key.

       Download the .p12 key file of the account and convert it to the .pem format:
       openssl pkcs12 -in XXX.p12  -nodes -nocerts > pydriveprivatekey.pem

       The content of .pem file should be passed to GOOGLE_DRIVE_ACCOUNT_KEY environment variable for
       authentification.

       The email address of the account will be used as part of URL. See URL FORMAT above.

       The alternative is to use a regular account. To do this, start as above, but when creating a new Client
       ID, select "Installed application" of type "Other". Create a file with the following content, and pass
       its filename in the GOOGLE_DRIVE_SETTINGS environment variable:

              client_config_backend: settings
              client_config:
                  client_id: <Client ID from developers' console>
                  client_secret: <Client secret from developers' console>
              save_credentials: True
              save_credentials_backend: file
              save_credentials_file: <filename to cache credentials>
              get_refresh_token: True

       In this scenario, the username and host parts of the URL play no role; only the path matters. During the
       first run, you will be prompted to visit an URL in your browser to grant access to your drive. Once
       granted, you will receive a verification code to paste back into Duplicity. The credentials are then
       cached in the file references above for future use.

A NOTE ON SSH BACKENDS

       The ssh backends support sftp and scp/ssh transport protocols.  This is a known user-confusing issue as
       these are fundamentally different.  If you plan to access your backend via one of those please inform
       yourself about the requirements for a server to support sftp or scp/ssh access.  To make it even more
       confusing the user can choose between several ssh backends via a scheme prefix: paramiko+ (default),
       pexpect+, lftp+... .
       paramiko & pexpect support --use-scp, --ssh-askpass and --ssh-options.  Only the pexpect backend allows
       to define --scp-command and --sftp-command.

       SSH paramiko backend (default) is a complete reimplementation of ssh protocols natively in python.
       Advantages are speed and maintainability. Minor disadvantage is that extra packages are needed as listed
       in REQUIREMENTS above. In sftp (default) mode all operations are done via the according sftp commands. In
       scp mode ( --use-scp ) though scp access is used for put/get operations but listing is done via ssh
       remote shell.

       SSH pexpect backend is the legacy ssh backend using the command line ssh binaries via pexpect.  Older
       versions used scp for get and put operations and sftp for list and delete operations.  The current
       version uses sftp for all four supported operations, unless the --use-scp option is used to revert to old
       behavior.

       SSH lftp backend is simply there because lftp can interact with the ssh cmd line binaries.  It is meant
       as a last resort in case the above options fail for some reason.

       Why use sftp instead of scp?  The change to sftp was made in order to allow the remote system to chroot
       the backup, thus providing better security and because it does not suffer from shell quoting issues like
       scp.  Scp also does not support any kind of file listing, so sftp or ssh access will always be needed in
       addition for this backend mode to work properly. Sftp does not have these limitations but needs an sftp
       service running on the backend server, which is sometimes not an option.

A NOTE ON SSL CERTIFICATE VERIFICATION

       Certificate verification as implemented right now [02.2016] only in the webdav and lftp backends. older
       pythons 2.7.8- and older lftp binaries need a file based database of certification authority certificates
       (cacert file).
       Newer python 2.7.9+ and recent lftp versions however support the system default certificates (usually in
       /etc/ssl/certs) and also giving an alternative ca cert folder via --ssl-cacert-path.

       The cacert file has to be a PEM formatted text file as currently provided by the CURL project. See

              http://curl.haxx.se/docs/caextract.html

       After creating/retrieving a valid cacert file you should copy it to either

              ~/.duplicity/cacert.pem
              ~/duplicity_cacert.pem
              /etc/duplicity/cacert.pem

       Duplicity searches it there in the same order and will fail if it can't find it.  You can however specify
       the option --ssl-cacert-file <file> to point duplicity to a copy in a different location.

       Finally there is the --ssl-no-check-certificate option to disable certificate verification alltogether,
       in case some ssl library is missing or verification is not wanted. Use it with care, as even with self
       signed servers manually providing the private ca certificate is definitely the safer option.

A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS

       Swift is the OpenStack Object Storage service.
       The backend requires python-switclient to be installed on the system.  python-keystoneclient is also
       needed to use OpenStack's Keystone Identity service.  See REQUIREMENTS above.

       It uses following environment variables for authentification: SWIFT_USERNAME (required), SWIFT_PASSWORD
       (required), SWIFT_AUTHURL (required), SWIFT_USERID (required, only for IBM Bluemix ObjectStorage),
       SWIFT_TENANTID (required, only for IBM Bluemix ObjectStorage), SWIFT_REGIONNAME (required, only for IBM
       Bluemix ObjectStorage), SWIFT_TENANTNAME (optional, the tenant can be included in the username)

       If the user was previously authenticated, the following environment variables can be used instead:
       SWIFT_PREAUTHURL (required), SWIFT_PREAUTHTOKEN (required)

       If SWIFT_AUTHVERSION is unspecified, it will default to version 1.

A NOTE ON MEDIAFIRE BACKEND

       This backend requires mediafire python library to be installed on the system. See REQUIREMENTS.

       Use URL escaping for username (and password, if provided via command line):

              mf://duplicity%40example.com@mediafire.com/some_folder

       The destination folder will be created for you if it does not exist.

A NOTE ON SYMMETRIC ENCRYPTION AND SIGNING

       Signing and symmetrically encrypt at the same time with the gpg binary on the command line, as used
       within duplicity, is a specifically challenging issue.  Tests showed that the following combinations
       proved working.

       1. Setup gpg-agent properly. Use the option --use-agent and enter both passphrases (symmetric and sign
       key) in the gpg-agent's dialog.

       2. Use a PASSPHRASE for symmetric encryption of your choice but the signing key has an empty passphrase.

       3. The used PASSPHRASE for symmetric encryption and the passphrase of the signing key are identical.

KNOWN ISSUES / BUGS

       Hard links currently unsupported (they will be treated as non-linked regular files).

       Bad signatures will be treated as empty instead of logging appropriate error message.

OPERATION AND DATA FORMATS

       This section describes duplicity's basic operation and the format of its data files.  It should not
       necessary to read this section to use duplicity.

       The files used by duplicity to store backup data are tarfiles in GNU tar format.  They can be produced
       independently by rdiffdir(1).  For incremental backups, new files are saved normally in the tarfile.  But
       when a file changes, instead of storing a complete copy of the file, only a diff is stored, as generated
       by rdiff(1).  If a file is deleted, a 0 length file is stored in the tar.  It is possible to restore a
       duplicity archive "manually" by using tar and then cp, rdiff, and rm as necessary.  These duplicity
       archives have the extension difftar.

       Both full and incremental backup sets have the same format.  In effect, a full backup set is an
       incremental one generated from an empty signature (see below).  The files in full backup sets will start
       with duplicity-full while the incremental sets start with duplicity-inc.  When restoring, duplicity
       applies patches in order, so deleting, for instance, a full backup set may make related incremental
       backup sets unusable.

       In order to determine which files have been deleted, and to calculate diffs for changed files, duplicity
       needs to process information about previous sessions.  It stores this information in the form of tarfiles
       where each entry's data contains the signature (as produced by rdiff) of the file instead of the file's
       contents.  These signature sets have the extension sigtar.

       Signature files are not required to restore a backup set, but without an up-to-date signature, duplicity
       cannot append an incremental backup to an existing archive.

       To save bandwidth, duplicity generates full signature sets and incremental signature sets.  A full
       signature set is generated for each full backup, and an incremental one for each incremental backup.
       These start with duplicity-full-signatures and duplicity-new-signatures respectively. These signatures
       will be stored both locally and remotely.  The remote signatures will be encrypted if encryption is
       enabled.  The local signatures will not be encrypted and stored in the archive dir (see --archive-dir ).

REQUIREMENTS

       Duplicity requires a POSIX-like operating system with a python interpreter version 2.6+ installed.  It is
       best used under GNU/Linux.

       Some backends also require additional components (probably available as packages for your specific
       platform):

       azure backend (Azure Blob Storage Service)
              Microsoft Azure Storage SDK for Python - https://pypi.python.org/pypi/azure-storage/

       boto backend (S3 Amazon Web Services, Google Cloud Storage)
              boto version 2.0+ - http://github.com/boto/boto

       cfpyrax backend (Rackspace Cloud) and hubic backend (hubic.com)
              Rackspace CloudFiles Pyrax API - http://docs.rackspace.com/sdks/guide/content/python.html

       dpbx backend (Dropbox)
              Dropbox Python SDK - https://www.dropbox.com/developers/reference/sdk

       copy backend (Copy.com)
              python-urllib3 - https://github.com/shazow/urllib3

       gdocs gdata backend (legacy Google Docs backend)
              Google Data APIs Python Client Library - http://code.google.com/p/gdata-python-client/

       gdocs pydrive backend(default)
              see pydrive backend

       gio backend (Gnome VFS API)
              PyGObject - http://live.gnome.org/PyGObject
              D-Bus (dbus)- http://www.freedesktop.org/wiki/Software/dbus

       lftp backend (needed for ftp, ftps, fish [over ssh] - also supports sftp, webdav[s])
              LFTP Client - http://lftp.yar.ru/

       mega backend (mega.co.nz)
              megatools client - https://github.com/megous/megatools

       multi backend
              Multi -- store to more than one backend
              (also see A NOTE ON MULTI BACKEND ) below.

       ncftp backend (ftp, select via ncftp+ftp://)
              NcFTP - http://www.ncftp.com/

       OneDrive backend (Microsoft OneDrive)
              python-requests - http://python-requests.org
              python-requests-oauthlib - https://github.com/requests/requests-oauthlib

       Par2 Wrapper Backend
              par2cmdline - http://parchive.sourceforge.net/

       pydrive backend
              PyDrive -- a wrapper library of google-api-python-client - https://pypi.python.org/pypi/PyDrive
              (also see A NOTE ON PYDRIVE BACKEND ) below.

       rsync backend
              rsync client binary - http://rsync.samba.org/

       ssh paramiko backend (default)
              paramiko (SSH2 for python) - http://pypi.python.org/pypi/paramiko (downloads);
              http://github.com/paramiko/paramiko (project page)
              pycrypto (Python Cryptography Toolkit) - http://www.dlitz.net/software/pycrypto/

       ssh pexpect backend
              sftp/scp client binaries OpenSSH - http://www.openssh.com/
              Python pexpect module - http://pexpect.sourceforge.net/pexpect.html

       swift backend (OpenStack Object Storage)
              Python swiftclient module - https://github.com/openstack/python-swiftclient/
              Python keystoneclient module - https://github.com/openstack/python-keystoneclient/

       webdav backend
              certificate authority database file for ssl certificate verification of HTTPS connections -
              http://curl.haxx.se/docs/caextract.html
              (also see A NOTE ON SSL CERTIFICATE VERIFICATION).
              Python kerberos module for kerberos authentication - https://github.com/02strich/pykerberos

       MediaFire backend
              MediaFire Python Open SDK - https://pypi.python.org/pypi/mediafire/

AUTHOR

       Original Author - Ben Escoto <bescoto@stanford.edu>

       Current Maintainer - Kenneth Loafman <kenneth@loafman.com>

       Continuous Contributors
              Edgar Soldin, Mike Terry

       Most backends were contributed individually.  Information about their authorship may be found in the
       according file's header.

       Also we'd like to thank everybody posting issues to the mailing list or on launchpad, sending in patches
       or contributing otherwise. Duplicity wouldn't be as stable and useful if it weren't for you.

       A special thanks goes to rsync.net, a Cloud Storage provider with explicit support for duplicity, for
       several monetary donations and for providing a special "duplicity friends" rate for their offsite backup
       service.  Email info@rsync.net for details.

SEE ALSO

       rdiffdir(1), python(1), rdiff(1), rdiff-backup(1).