NAME

       s3qllock - Make trees on an S3QL file system immutable

SYNOPSIS

          s3qllock [options] <directory>

DESCRIPTION

       S3QL  is  a  file  system  for  online  data  storage.  Before  using S3QL, make sure to consult the full
       documentation (rather than just the man  pages  which  only  briefly  document  the  available  userspace
       commands).

       The  s3qllock  command  makes  a  directory tree in an S3QL file system immutable. Immutable trees can no
       longer be changed in any way whatsoever. You can not add new files or directories and you can not  change
       or  delete  existing  files  and  directories. The only way to get rid of an immutable tree is to use the
       s3qlrm command.

       s3qllock can only be called by the user that mounted the file system and (if the file system was  mounted
       with  --allow-other  or  --allow-root) the root user. This limitation might be removed in the future (see
       issue 155).

RATIONALE

       Immutability is a feature designed for backups. Traditionally, backups have been made  on  external  tape
       drives.  Once a backup was made, the tape drive was removed and locked somewhere in a shelf. This has the
       great advantage that the contents of the backup are now permanently fixed.  Nothing  (short  of  physical
       destruction) can change or delete files in the backup.

       In  contrast,  when  backing  up into an online storage system like S3QL, all backups are available every
       time the file system is mounted.  Nothing prevents a file in an old backup from being changed again later
       on. In the worst case, this may make your entire backup system worthless. Imagine that your  system  gets
       infected  by  a nasty virus that simply deletes all files it can find -- if the virus is active while the
       backup file system is mounted, the virus will destroy all your old backups as well!

       Even if the possibility of a malicious virus or trojan horse is excluded, being able to change  a  backup
       after  it  has  been made is generally not a good idea. A common S3QL use case is to keep the file system
       mounted at all times and periodically create backups with rsync -a. This allows every user to recover her
       files from a backup without having to call the system administrator. However, this also allows every user
       to accidentally change or delete files in one of the old backups.

       Making a backup immutable protects you against all these problems.  Unless you happen to run into a virus
       that was specifically programmed to attack S3QL file systems, backups can be neither deleted nor  changed
       after they have been made immutable.

OPTIONS

       The s3qllock command accepts the following options:

          --debug
                 activate debugging output

          --quiet
                 be really quiet

          --version
                 just print program version and exit

EXIT STATUS

       s3qllock returns exit code 0 if the operation succeeded and 1 if some error occurred.

SEE ALSO

       The S3QL homepage is at http://code.google.com/p/s3ql/.

       The  full  S3QL  documentation  should  also  be installed somewhere on your system, common locations are
       /usr/share/doc/s3ql or /usr/local/doc/s3ql.

COPYRIGHT

       2008-2011, Nikolaus Rath

1.16                                              July 14, 2013                                      S3QLLOCK(1)