Provided by: snapper_0.1.8-2_amd64 bug

NAME

       snapper - Command-line program for filesystem snapshot management

SYNOPSIS

       snapper [--global-opts] command [--command-opts] [command-arguments]

       snapper {--help}

DESCRIPTION

       Snapper is a command-line program for filesystem snapshot management. It can create,
       delete and compare snapshots and undo changes done between snapshots.

       Snapper never modifies the content of snapshots. Thus snapper creates read-only snapshots
       if supported by the kernel. Supported filesystems are btrfs and ext4 as well as snapshots
       of LVM logical volumes with thin-provisioning. Some filesystems might not be supported
       depending on your installation.

CONCEPTS

   Configurations
       For each filesystem or subvolume that should be snapshotted by snapper, a configuration
       file is required, see snapper-configs(5). The setup can be done with the create-config
       command.

   Snapshots
       Snapper distinguishes three types of snapshots.

       pre
           Pre snapshots should always have a corresponding post snapshot. The intention of
           pre/post snapshot pairs is to snapshot the filesystem before and after a modification.

       post
           See pre type.

       single
           These snapshots have no special relationship to other snapshots.

       Note that filesystem-wise all three types are the same.

   Snapshot Description and Userdata
       With each snapshot a description and some userdata can be associated. The description is a
       string. The userdata is a list of key-value pairs where the keys and values are strings.

   Automatic Snapshot Creation
       Next to manual snapshot creation, snapshots are also created automatically.

       •   A cron-job creates hourly snapshots.

       •   Certain programs like YaST and zypper create pre/post snapshot pairs when modifying
           the system.

   Cleanup Algorithms
       Snapper provides several algorithms to clean up old snapshots. The algorithms are executed
       in a daily cron-job. This can be configured in the corresponding configurations files
       along with parameters for every algorithm.

       number
           Deletes old snapshots when a certain number of snapshots is reached.

       timeline
           Deletes old snapshots but keeps a number of hourly, daily, monthly and yearly
           snapshots.

       empty-pre-post
           Deletes pre/post snapshot pairs with empty diffs.

   Filters
       Some files keep state information of the system, e.g.  /etc/mtab. Such files should never
       be reverted. To help users, snapper allows to ignore these files.

       Each line in all files /etc/snapper/filters/*.txt specifies a pattern. When snapper
       computes the difference between two snapshots it ignores all files and directories
       matching any of those patterns by using fnmatch(3) with the flag FNM_LEADING_DIR.

       Note that filters do not exclude files or directories from being snapshotted. For that,
       use subvolumes or mount points.

GLOBAL OPTIONS

       -q, --quiet
           Suppress normal output. Error messages will still be printed, though.

       -v, --verbose
           Increase verbosity.

       -t, --table-style
           Specifies table style. Table style is identified by an integer number.

       -c, --config name
           Use specified configuration instead of the default configuration. The default
           configuration is named "root".

       --no-dbus
           Operate without a DBus connection. Only works for some commands.

           Use with caution since a running snapperd will not know about modifications made to
           the system.

       --version
           Print version and exit.

COMMANDS

       Snapper provides a number of commands. Each command accepts the options listed in the
       GLOBAL OPTIONS section. These options must be specified before the command name. In
       addition, many commands have specific options, which are listed in this section. These
       command-specific options must be specified after the name of the command and before any of
       the command arguments.

       help
           Show short help text.

       list-configs
           List available configurations.

       create-config [options] subvolume
           Create a new configuration for a filesystem or subvolume. For this command you will
           likely need the global option --config, see GLOBAL OPTIONS and CONCEPTS.

           -f, --fstype fstype
               Manually set filesystem type. Supported values are btrfs, ext4 and lvm. For lvm,
               snapper uses LVM thin-provisioned snapshots. The filesystem type on top of LVM
               must be provided in parentheses, e.g. lvm(xfs).

               Without this option snapper tries to detect the filesystem.

           -t, --template name
               Name of template for the new configuration file.

       delete-config
           Delete a configuration for a filesystem or subvolume. For this command you will likely
           need to global option --config, see GLOBAL OPTIONS and CONCEPTS.

       get-config
           Displays the settings of the configuration.

       set-config configdata
           Changes the settings of the configuration. The settings configdata are a list of
           key-value-pairs separated by spaces and the key and value must be separated by an
           equal sign, e.g. "NUMBER_CLEANUP=yes NUMBER_LIMIT=10". The value of SUBVOLUME and
           FSTYPE cannot be changed.

       list [options]
           List snapshots.

           -t, --type type
               Selects type of snapshots to list. Possible values are all, single and pre-post.

       create [options]
           Create a new snapshot.

           -t, --type type
               Specifies the type of the new snapshot. Possible values are single, pre and post.

           --pre-number number
               For post snapshots the number of the pre snapshot must be provided.

           -p, --print-number
               Print number of the created snapshot.

           -d, --description description
               Description for the snapshot.

           -c, --cleanup-algorithm cleanup-algorithm
               Set the cleanup algorithm for the snapshot.

           -u, --userdata userdata
               Set userdata for the snapshot. The key-value pairs must be separated by comma and
               the key and value must be separated by an equal sign, e.g.
               requestid=42,user=arthur.

           --command command
               Create a pre and post snapshot and run command in between.

       modify [options] number
           Modify a snapshot.

           -d, --description description
               New description for snapshot.

           -c, --cleanup-algorithm cleanup-algorithm
               Set the cleanup algorithm for the snapshot.

           -u, --userdata userdata
               Set userdata for the snapshot. The key-value pairs must be separated by comma and
               the key and value must be separated by an equal sign, e.g.
               requestid=42,user=arthur.

       delete number | number1-number2
           Delete a snapshot or a range of snapshots.

       mount number
           Mount a snapshot. Not required for all filesystem types.

       umount number
           Unmount a snapshot. Not required for all filesystem types.

       status [options] number1..number2
           Compare the snapshots number1 and number2. This will show a list of files and
           directories that have been created, modified or deleted in the time between the two
           snapshots have been made.

           -o, --output file
               Write output to file file.

       diff [options] number1..number2 [files]
           Compare the snapshots number1 and number2. This will show a diff of the content of
           files and directories that have been created, modified or deleted in the time between
           the two snapshots have been made.

       undochange [options] number1..number2 [files]
           Undo changes done between snapshot number1 and number2.

           -i, --input file
               Read files for which to undo changes from file file.

       cleanup cleanup-algorithm
           Run the cleanup algorithm cleanup-algorithm. Currently implemented cleanup algorithms
           are number, timeline and empty-pre-post.

       xadiff number1..number2 [files]
           Compare the extended attributes between snapshot number1 and number2. See examples
           below:

           •   +:user.foo for created attributes

           •   -:user.bar for removed attributes

           •   -+:security.selinux for modified attributes

PERMISSIONS

       Non-root users can be allowed to use a configuration by setting ALLOW_USERS or
       ALLOW_GROUPS in the config file. For all operations to work, the user must also be able to
       read and access the .snapshots directory inside the subvolume. The .snapshots directory
       must be owned by root and must not be writable by anybody else.

FILES

       /etc/sysconfig/snapper
           Global configuration file.

       /etc/snapper/configs
           Directory containing configuration files.

       /etc/snapper/config-templates
           Directory containing configuration templates.

       /etc/snapper/filters/*.txt
           Filter files.

       /var/log/snapper.log
           Logfile. Please include this file in bug reports.

NOTES

       There is no mechanism to ensure consistency of the files while a snapshot it made. E.g.
       the files of a database can be inconsistent while the database is running.

       Consistency after undochange is not guaranteed. E.g. when the creation of a user is
       undone, there might still exist files from that user.

       Support for extended attributes is a compile-time option.

HOMEPAGE

       http://snapper.io/

AUTHORS

       Arvin Schnell <aschnell@suse.de>

SEE ALSO

       snapper-configs(5), pam_snapper(8), btrfs(8), lvm(8), attr(5)