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NAME
       rdiff-backup - local/remote mirror and incremental backup

SYNOPSIS
       rdiff-backup      [options]      [[[user@]host1.foo]::source_directory]
       [[[user@]host2.foo]::destination_directory]

       rdiff-backup  {{  -l  |  --list-increments  }   |   --remove-older-than
       time_interval  |  --list-at-time  time  |  --list-changed-since  time |
       --list-increment-sizes   |   --verify    |    --verify-at-time    time}
       [[[user@]host2.foo]::destination_directory]

       rdiff-backup --calculate-average statfile1 statfile2 ...

       rdiff-backup           --test-server           [user1]@host1.net1::path
       [[user2]@host2.net2::path] ...


DESCRIPTION
       rdiff-backup is a script, written in python(1) that backs up one direc-
       tory  to  another.  The target directory ends up a copy (mirror) of the
       source directory, but extra reverse diffs are stored in a special  sub-
       directory of that target directory, so you can still recover files lost
       some time ago.  The idea is to combine the best features  of  a  mirror
       and  an incremental backup.  rdiff-backup also preserves symlinks, spe-
       cial files, hardlinks, permissions, uid/gid ownership, and modification
       times.

       rdiff-backup  can  also  operate in a bandwidth efficient manner over a
       pipe, like rsync(1).  Thus you can use ssh and rdiff-backup to securely
       back  a  hard  drive  up to a remote location, and only the differences
       will be transmitted.  Using the default settings, rdiff-backup requires
       that the remote system accept ssh connections, and that rdiff-backup is
       installed in the user's PATH on the remote system.  For information  on
       other options, see the section on REMOTE OPERATION.

       Note  that  you  should  not  write to the mirror directory except with
       rdiff-backup.  Many of the increments are stored as reverse  diffs,  so
       if  you  delete  or  modify a file, you may lose the ability to restore
       previous versions of that file.

       Finally, this man page is intended more as a precise description of the
       behavior  and  syntax of rdiff-backup.  New users may want to check out
       the examples.html file included in the rdiff-backup distribution.


OPTIONS
       -b, --backup-mode
              Force backup mode even if first argument appears to be an incre-
              ment or mirror file.

       --calculate-average
              Enter  calculate average mode.  The arguments should be a number
              of statistics files.  rdiff-backup will print the average of the



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              listed statistics files and exit.

       --carbonfile
              Enable backup of MacOS X carbonfile information.

       --check-destination-dir
              If an rdiff-backup session fails, running rdiff-backup with this
              option on the destination dir will undo  the  failed  directory.
              This happens automatically if you attempt to back up to a direc-
              tory and the last backup failed.

       --compare
              This is equivalent to '--compare-at-time now'

       --compare-at-time time
              Compare a directory with the backup set at the given time.  This
              can  be  useful  to  see  how archived data differs from current
              data, or to check that a backup is current.  This only  compares
              metadata,  in  the  same way rdiff-backup decides whether a file
              has changed.

       --compare-full
              This is equivalent to '--compare-full-at-time now'

       --compare-full-at-time time
              Compare a directory with the backup set at the given  time.   To
              compare regular files, the repository data will be copied in its
              entirety to the source side and compared byte by byte.  This  is
              the slowest but most complete compare option.

       --compare-hash
              This is equivalent to '--compare-hash-at-time now'

       --compare-hash-at-time time
              Compare a directory with the backup set at the given time.  Reg-
              ular files will be compared by computing their  SHA1  digest  on
              the  source  side and comparing it to the digest recorded in the
              metadata.

       --create-full-path
              Normally only the final directory of the destination  path  will
              be  created  if it does not exist. With this option, all missing
              directories on the destination path will be  created.  Use  this
              option  with  care:  if  there is a typo in the remote path, the
              remote filesystem could fill up  very  quickly  (by  creating  a
              duplicate backup tree). For this reason this option is primarily
              aimed at scripts which automate backups.

       --current-time seconds
              This option is useful mainly for testing.  If set,  rdiff-backup
              will  use  it  for  the  current  time instead of consulting the
              clock.  The argument is the number of seconds since the epoch.





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       --exclude shell_pattern
              Exclude the file or files matched by shell_pattern.  If a direc-
              tory  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/per-
              missions reasons or if rdiff-backup is not handling device files
              correctly.

       --exclude-fifos
              Exclude all fifo files.

       --exclude-filelist filename
              Excludes the files listed in filename.  If filename is handwrit-
              ten  you probably want --exclude-globbing-filelist instead.  See
              the FILE SELECTION section for more information.

       --exclude-filelist-stdin
              Like --exclude-filelist, but the list of files will be read from
              standard  input.  See the FILE SELECTION section for more infor-
              mation.

       --exclude-globbing-filelist filename
              Like --exclude-filelist but each line of the  filelist  will  be
              interpreted  according  to  the  same  rules  as  --include  and
              --exclude.

       --exclude-globbing-filelist-stdin
              Like --exclude-globbing-filelist, but the list of files will  be
              read from standard input.

       --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.

       --exclude-special-files
              Exclude all device files, fifo files, socket files, and symbolic
              links.

       --exclude-sockets
              Exclude all socket files.

       --exclude-symbolic-links
              Exclude all symbolic links. This option is automatically enabled
              if the backup source is running on native Windows to avoid back-
              ing-up NTFS reparse points.




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       --exclude-if-present filename
              Exclude directories if filename is present. This option needs to
              come before any other include or exclude options.

       --force
              Authorize  a more drastic modification of a directory than usual
              (for instance, when overwriting of a destination path,  or  when
              removing  multiple  sessions  with --remove-older-than).  rdiff-
              backup will generally tell you if it needs this.   WARNING:  You
              can cause data loss if you mis-use this option.  Furthermore, do
              NOT use this option when doing a  restore,  as  it  will  DELETE
              FILES, unless you absolutely know what you are doing.

       --group-mapping-file filename
              Map  group  names  and  ids according the the group mapping file
              filename.  See the USERS AND GROUPS section  for  more  informa-
              tion.

       --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.
              If filename is handwritten you probably want --include-globbing-
              filelist instead.  See  the  FILE  SELECTION  section  for  more
              information.

       --include-filelist-stdin
              Like  --include-filelist,  but  read  the list of included files
              from standard input.

       --include-globbing-filelist filename
              Like --include-filelist but each line of the  filelist  will  be
              interpreted  according  to  the  same  rules  as  --include  and
              --exclude.

       --include-globbing-filelist-stdin
              Like --include-globbing-filelist, but the list of files will  be
              read from standard input.

       --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.

       --include-special-files
              Include all device files, fifo files, socket files, and symbolic
              links.

       --include-symbolic-links
              Include all symbolic links.



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       --list-at-time time
              List the files in the archive that were  present  at  the  given
              time.  If a directory in the archive is specified, list only the
              files under that directory.

       --list-changed-since time
              List the files that have changed in  the  destination  directory
              since  the given time.  See TIME FORMATS for the format of time.
              If a directory in the archive is specified, list only the  files
              under  that  directory.   This  option  does not read the source
              directory; it is used to compare the contents of  two  different
              rdiff-backup sessions.

       -l, --list-increments
              List  the  number  and  date of partial incremental backups con-
              tained in the specified destination  directory.   No  backup  or
              restore will take place if this option is given.

       --list-increment-sizes
              List  the  total  size  of all the increment and mirror files by
              time.  This may be helpful in deciding how  many  increments  to
              keep,  and  when to --remove-older-than.  Specifying a subdirec-
              tory is allowable; then only the sizes of the mirror and  incre-
              ments pertaining to that subdirectory will be listed.

       --max-file-size size
              Exclude files that are larger than the given size in bytes

       --min-file-size size
              Exclude files that are smaller than the given size in bytes

       --never-drop-acls
              Exit  with  error instead of dropping acls or acl entries.  Nor-
              mally this may happen (with a warning) because  the  destination
              does  not  support them or because the relevant user/group names
              do not exist on the destination side.

       --no-acls
              No Access Control Lists - disable backup of ACLs

       --no-carbonfile
              Disable backup of MacOS X carbonfile information

       --no-compare-inode
              This option prevents rdiff-backup  from  flagging  a  hardlinked
              file  as  changed  when  its device number and/or inode changes.
              This option is useful in situations where the source  filesystem
              lacks  persistent  device  and/or inode numbering.  For example,
              network filesystems may have mount-to-mount differences in their
              device  number  (but  possibly  stable  inode numbers); USB/1394
              devices may come up at different  device  numbers  each  remount
              (but  would  generally  have  same  inode number); and there are
              filesystems which don't even have the same  inode  numbers  from
              use  to  use.   Without  the  option  rdiff-backup  may generate



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              unnecessary numbers of tiny diff files.

       --no-compression
              Disable the default gzip compression of most  of  the  .snapshot
              and .diff increment files stored in the rdiff-backup-data direc-
              tory.  A backup volume can contain compressed  and  uncompressed
              increments, so using this option inconsistently is fine.

       --no-compression-regexp  regexp
              Do  not compress increments based on files whose filenames match
              regexp.   The  default  includes  many  common  audiovisual  and
              archive files, and may be found in Globals.py.

       --no-eas
              No Extended Attributes support - disable backup of EAs.

       --no-file-statistics
              This  will  disable  writing  to the file_statistics file in the
              rdiff-backup-data directory.   rdiff-backup  will  run  slightly
              quicker and take up a bit less space.

       --no-hard-links
              Don't  replicate  hard links on destination side.  If many hard-
              linked files are present, this option can  drastically  decrease
              memory  usage.   This option is enabled by default if the backup
              source or restore destination is running on native Windows.

       --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[-stdin]  switches  as  well  as the
              format of the directory statistics file.

       --parsable-output
              If set, rdiff-backup's output will be tailored for easy  parsing
              by computers, instead of convenience for humans.  Currently this
              only applies when listing increments using  the  -l  or  --list-
              increments  switches,  where  the  time will be given in seconds
              since the epoch.

       --override-chars-to-quote
              If the filesystem to which we are backing up is not  case-sensi-
              tive,  automatic  'quoting' of characters occurs. For example, a
              file 'Developer.doc' will be converted into  ';068eveloper.doc'.
              To override this behavior, you need to specify this option.

       --preserve-numerical-ids
              If  set,  rdiff-backup will preserve uids/gids instead of trying
              to preserve unames and gnames.  See the USERS AND GROUPS section
              for more information.

       --print-statistics
              If  set,  summary  statistics will be printed after a successful



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              backup.  If not set, this information will  still  be  available
              from  the  session  statistics file.  See the STATISTICS section
              for more information.

       -r, --restore-as-of restore_time
              Restore the specified directory as it was  as  of  restore_time.
              See  the TIME FORMATS section for more information on the format
              of restore_time, and see the RESTORING section for more informa-
              tion on restoring.

       --remote-cmd cmd
              Deprecated. Please use --remote-schema instead

       --remote-schema schema
              Specify  an alternate method of connecting to a remote computer.
              This is necessary to get rdiff-backup not to use ssh for  remote
              backups, or if, for instance, rdiff-backup is not in the PATH on
              the remote side.  See the  REMOTE  OPERATION  section  for  more
              information.

       --remote-tempdir path
              Adds  the  --tempdir  option  with  argument  path when invoking
              remote instances of rdiff-backup.

       --remove-older-than time_spec
              Remove the incremental backup  information  in  the  destination
              directory  that  has  been  around  longer  than the given time.
              time_spec can be either an absolute time, like "2002-01-04",  or
              a  time  interval.   The time interval is an integer followed by
              the character s, m, h, D, W, M, or Y, indicating  seconds,  min-
              utes,  hours,  days,  weeks, months, or years respectively, or a
              number of these concatenated.  For example, 32m  means  32  min-
              utes,  and 3W2D10h7s means 3 weeks, 2 days, 10 hours, and 7 sec-
              onds.  In this context, a month means 30 days,  a  year  is  365
              days, and a day is always 86400 seconds.

              rdiff-backup  cannot remove-older-than and back up or restore in
              a single session.  In order  to  both  backup  a  directory  and
              remove old files in it, you must run rdiff-backup twice.

              By  default,  rdiff-backup will only delete information from one
              session at a time.  To remove two or more sessions at  the  same
              time,  supply  the --force option (rdiff-backup will tell you if
              --force is required).

              Note that snapshots of deleted files are covered by this  opera-
              tion.  Thus if you deleted a file two weeks ago, backed up imme-
              diately afterwards, and then  ran  rdiff-backup  with  --remove-
              older-than  10D  today,  no  trace  of  that  file would remain.
              Finally, file selection options such as --include and  --exclude
              don't affect --remove-older-than.

       --restrict path
              Require  that  all  file  access be inside the given path.  This



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              switch, and the following two, are intended to be used with  the
              --server  switch  to  provide  a  bit more protection when doing
              automated remote backups.  They are not intended  as  your  only
              line  of  defense  so please don't do something silly like allow
              public access to an rdiff-backup  server  run  with  --restrict-
              read-only.

       --restrict-read-only path
              Like --restrict, but also reject all write requests.

       --restrict-update-only path
              Like --restrict, but only allow writes as part of an incremental
              backup.  Requests for  other  types  of  writes  (for  instance,
              deleting path) will be rejected.

       --server
              Enter  server mode (not to be invoked directly, but instead used
              by another rdiff-backup process on a remote computer).

       --ssh-no-compression
              When running ssh, do not use the -C option  to  enable  compres-
              sion.   --ssh-no-compression  is  ignored  if  you specify a new
              schema using --remote-schema.

       --tempdir path
              Sets the directory that rdiff-backup uses for temporary files to
              the  given path. The environment variables TMPDIR, TEMP, and TMP
              can also be used to set the temporary files directory.  See  the
              documentation  of  the  Python tempfile module for more informa-
              tion.

       --terminal-verbosity [0-9]
              Select which messages will be displayed  to  the  terminal.   If
              missing the level defaults to the verbosity level.

       --test-server
              Test  for  the  presence  of a compatible rdiff-backup server as
              specified in  the  following  host::filename  argument(s).   The
              filename section will be ignored.

       --user-mapping-file filename
              Map  user names and ids according to the user mapping file file-
              name.  See the USERS AND GROUPS section for more information.

       -v[0-9], --verbosity [0-9]
              Specify verbosity level (0 is totally silent, 3 is the  default,
              and  9 is noisiest).  This determines how much is written to the
              log file.

       --verify
              This is short for --verify-at-time now

       --verify-at-time now
              Check all the data in  the  repository  at  the  given  time  by



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              computing  the  SHA1 hash of all the regular files and comparing
              them with the hashes stored in the metadata file.

       -V, --version
              Print the current version and exit


RESTORING
       There are two ways to tell rdiff-backup to restore a file or directory.
       Firstly,  you  can  run rdiff-backup on a mirror file and use the -r or
       --restore-as-of options.  Secondly, you can  run  it  on  an  increment
       file.

       For example, suppose in the past you have run:

              rdiff-backup /usr /usr.backup

       to  back  up the /usr directory into the /usr.backup directory, and now
       want a copy of the /usr/local directory the  way  it  was  3  days  ago
       placed at /usr/local.old.

       One way to do this is to run:

              rdiff-backup -r 3D /usr.backup/local /usr/local.old

       where  above the "3D" means 3 days (for other ways to specify the time,
       see the TIME FORMATS section).   The  /usr.backup/local  directory  was
       selected,  because that is the directory containing the current version
       of /usr/local.

       Note that the option to --restore-as-of always specifies an exact time.
       (So  "3D" refers to the instant 72 hours before the present.)  If there
       was no backup made  at  that  time,  rdiff-backup  restores  the  state
       recorded  for the previous backup.  For instance, in the above case, if
       "3D" is used, and there are only backups from 2 days and  4  days  ago,
       /usr/local as it was 4 days ago will be restored.

       The  second  way  to  restore  files involves finding the corresponding
       increment file.  It would be  in  the  /backup/rdiff-backup-data/incre-
       ments/usr   directory,   and   its   name   would   be  something  like
       "local.2002-11-09T12:43:53-04:00.dir" where the time  indicates  it  is
       from  3  days  ago.   Note that the increment files all end in ".diff",
       ".snapshot", ".dir", or ".missing", where ".missing"  just  means  that
       the file didn't exist at that time (finally, some of these may be gzip-
       compressed, and have an extra ".gz" to indicate this).  Then running:

              rdiff-backup                    /backup/rdiff-backup-data/incre-
              ments/usr/local.<time>.dir /usr/local.old

       would also restore the file as desired.

       If  you  are  not  sure exactly which version of a file you need, it is
       probably easiest  to  either  restore  from  the  increments  files  as
       described  immediately  above, or to see which increments are available



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       with  -l/--list-increments,  and  then   specify   exact   times   into
       -r/--restore-as-of.


TIME FORMATS
       rdiff-backup  uses  time  strings  in  two places.  Firstly, all of the
       increment files rdiff-backup creates will have the time in their  file-
       names  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 -r, --restore-as-of, and --remove-older-than 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  timezone  settings.   For  instance,
              "2002/3/5", "03-05-2002", and "2002-3-05" all  mean  March  5th,
              2002.

       6.     A  backup  session specification which is a non-negative integer
              followed by 'B'.  For instance, '0B' specifies the time  of  the
              current  mirror,  and  '3B' specifies the time of the 3rd newest
              increment.


REMOTE OPERATION
       In order to access remote files, rdiff-backup opens up a pipe to a copy
       of  rdiff-backup running on the remote machine.  Thus rdiff-backup must
       be installed on both ends.   To  open  this  pipe,  rdiff-backup  first
       splits  the  filename  into  host_info::pathname.   It then substitutes
       host_info into the remote schema, and runs the resulting command, read-
       ing its input and output.

       The  default  remote  schema is 'ssh -C %s rdiff-backup --server' where
       host_info  is  substituted  for  '%s'.   So   if   the   host_info   is
       user@host.net,  then  rdiff-backup runs 'ssh user@host.net rdiff-backup



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       --server'.  Using --remote-schema, rdiff-backup can invoke an arbitrary
       command in order to open up a remote pipe.  For instance,
              rdiff-backup  --remote-schema  'cd  /usr;  %s' foo 'rdiff-backup
              --server'::bar
       is basically equivalent to (but slower than)
              rdiff-backup foo /usr/bar

       Concerning quoting, if for some reason you need to put two  consecutive
       colons  in  the host_info section of a host_info::pathname argument, or
       in the pathname of a local file, you can quote one of them by  prepend-
       ing  a  backslash.  So in 'a\::b::c', host_info is 'a::b' and the path-
       name is 'c'.  Similarly, if you want to refer to  a  local  file  whose
       filename  contains two consecutive colons, like 'strange::file', you'll
       have to quote one of the colons as in  'strange\::file'.   Because  the
       backslash  is  a quote character in these circumstances, it too must be
       quoted to get  a  literal  backslash,  so  'foo\::\\bar'  evaluates  to
       'foo::\bar'.  To make things more complicated, because the backslash is
       also a common shell quoting character, you may need to type  in  '\\\\'
       at  the  shell  prompt to get a literal backslash (if it makes you feel
       better, I had to type  in  8  backslashes  to  get  that  in  this  man
       page...).   And finally, to include a literal % in the string specified
       by --remote-schema, quote it with another %, as in %%.

       Although ssh itself may be secure, using rdiff-backup  in  the  default
       way presents some security risks.  For instance if the server is run as
       root, then an attacker who compromised the client could then use rdiff-
       backup  to  overwrite arbitrary server files by "backing up" over them.
       Such a setup can be made more secure by using  the  sshd  configuration
       option   command="rdiff-backup   --server"   possibly  along  with  the
       --restrict* options to rdiff-backup.  For more information, see the web
       page, the wiki, and the entries for the --restrict* options on this man
       page.


FILE SELECTION
       rdiff-backup has a number of file selection options.  When rdiff-backup
       is run, it searches through the given source directory and backs up all
       the files matching the specified options.  This  selection  system  may
       appear  complicated, but it is supposed to be flexible and easy-to-use.
       If you just want to learn the basics, first look at the selection exam-
       ples  in  the examples.html file included in the package, or on the web
       at http://rdiff-backup.nongnu.org/examples.html

       rdiff-backup's selection system was originally  inspired  by  rsync(1),
       but  there  are  many differences.  (For instance, trailing backslashes
       have no special significance.)

       The file selection system comprises a number of file  selection  condi-
       tions,  which  are set using one of the following command line options:
       --exclude, --exclude-filelist, --exclude-device-files, --exclude-fifos,
       --exclude-sockets,     --exclude-symbolic-links,    --exclude-globbing-
       filelist, --exclude-globbing-filelist-stdin,  --exclude-filelist-stdin,
       --exclude-regexp,    --exclude-special-files,   --include,   --include-
       filelist,   --include-globbing-filelist,   --include-globbing-filelist-



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       stdin,   --include-filelist-stdin,  and  --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.  When backing up, if a file
       is excluded, rdiff-backup acts as if that file does not  exist  in  the
       source  directory.   When restoring, an excluded file is considered not
       to exist in either the source or target directories.

       For instance,

              rdiff-backup --include /usr --exclude /usr /usr /backup

       is exactly the same as

              rdiff-backup /usr /backup

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

              rdiff-backup --include /usr/local/bin --exclude /usr/local  /usr
              /backup

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

       The include, exclude, include-globbing-filelist, and  exclude-globbing-
       filelist  options  accept extended shell globbing patterns.  These pat-
       terns can contain the special patterns *, **, ?, and [...].   As  in  a
       normal  shell,  *  can be expanded to any string of characters not con-
       taining "/", ?  expands to any character except "/", and [...]  expands
       to a single character of those characters specified (ranges are accept-
       able).  The new special pattern, **, expands to any string  of  charac-
       ters  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.

       If you need to match filenames which contain the above globbing charac-
       ters,  they  may  be  escaped using a backslash "\". The backslash will
       only escape the character following it so for ** you will need  to  use
       "\*\*" to avoid escaping it to the * globbing character.

       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 rdiff-backup sees them.

       The --exclude pattern option matches a file iff:

       1.     pattern can be expanded into the file's filename, or

       2.     the file is inside a directory matched by the option.

       Conversely, --include pattern matches a file iff:



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       1.     pattern can be expanded into the file's filename,

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

              --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.

       The  --include-filelist,  --exclude-filelist, --include-filelist-stdin,
       and --exclude-filelist-stdin options also introduce file selection con-
       ditions.   They  direct  rdiff-backup  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  a  filelist  is
       interpreted  similarly  to  the way extended shell patterns are, with a
       few exceptions:

       1.     Globbing patterns like *, **, ?, and [...]  are not expanded.

       2.     Include patterns do not match  files  in  a  directory  that  is
              included.   So  /usr/local  in  an  include  file will not match
              /usr/local/doc.

       3.     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 the file "list.txt" contains the lines:

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



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              - /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   neither   excludes  nor  includes
       /usr/local/man, leaving the fate of this directory to the next specifi-
       cation  condition.  Finally, it is undefined what happens with /var.  A
       single file list should not contain conflicting file specifications.

       The --include-globbing-filelist and --exclude-globbing-filelist options
       also  specify  filelists,  but each line in the filelist will be inter-
       preted as a globbing pattern the way --include  and  --exclude  options
       are  interpreted  (although  "+ " and "- " prefixing is still allowed).
       For instance, if the file "globbing-list.txt" contains the lines:

              dir/foo
              + dir/bar
              - **

       Then "--include-globbing-filelist globbing-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 allow  files  to  be
       included and excluded if their filenames match a python regular expres-
       sion.  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.


USERS AND GROUPS
       There  can  be  complications preserving ownership across systems.  For
       instance the username that owns a file on the  source  system  may  not
       exist  on  the destination.  Here is how rdiff-backup maps ownership on
       the source to the destination (or vice-versa, in the  case  of  restor-
       ing):


       1.     If  the  --preserve-numerical-ids  option  is  given, the remote
              files will always have the same uid and gid, both for  ownership
              and ACL entries.  This may cause unames and gnames to change.

       2.     Otherwise, attempt to preserve the user and group names for own-
              ership and in ACLs.  This may result in files  having  different
              uids and gids across systems.

       3.     If  a  name  cannot be preserved (e.g. because the username does



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              not exist), preserve the original id, but only in cases of  user
              and  group  ownership.   For ACLs, omit any entry that has a bad
              user or group name.

       4.     The --user-mapping-file and --group-mapping-file  options  over-
              ride  this  behavior.   If either of these options is given, the
              policy described in 2 and 3 above will be followed, but with the
              mapped  user  and group instead of the original.  If you specify
              both --preserve-numerical-ids and one of  the  mapping  options,
              the behavior is undefined.

       The user and group mapping files both have the same form:

              old_name_or_id1:new_name_or_id1
              old_name_or_id2:new_name_or_id2
              <etc>

       Each  line  should  contain a name or id, followed by a colon ":", fol-
       lowed by another name or id.  If a name or id is not listed,  they  are
       treated in the default way described above.

       When  restoring, the above behavior is also followed, but note that the
       original source user/group information  will  be  the  input,  not  the
       already mapped user/group information present in the backup repository.
       For instance, suppose you have mapped all the files owned by  alice  in
       the source so that they are owned by ben in the repository, and now you
       want to restore, making sure the files owned originally  by  alice  are
       still  owned by alice.  In this case there is no need to use any of the
       mapping options.  However, if you wanted to restore the files  so  that
       the files originally owned by alice on the source are now owned by ben,
       you would have to use the mapping options, even though  you  just  want
       the unames of the repository's files preserved in the restored files.



STATISTICS
       Every session rdiff-backup saves various statistics into two files, the
       session   statistics    file    at    rdiff-backup-data/session_statis-
       tics.<time>.data  and  the  directory  statistics file at rdiff-backup-
       data/directory_statistics.<time>.data.  They are both  text  files  and
       contain  similar  information:  how  many  files changed, how many were
       deleted, the total size of increment files created, etc.  However,  the
       session  statistics  file  is  intended  to  be  very readable and only
       describes the session as a whole.  The  directory  statistics  file  is
       more compact (and slightly less readable) but describes every directory
       backed up.  It also may be compressed to save space.

       Statistics-related options include --print-statistics and  --null-sepa-
       rator.

       Also, rdiff-backup will save various messages to the log file, which is
       rdiff-backup-data/backup.log  for  backup  sessions  and  rdiff-backup-
       data/restore.log  for  restore  sessions.  Generally what is written to
       this file will coincide  with  the  messages  displayed  to  stdout  or



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       stderr,  although  this  can  be  changed with the --terminal-verbosity
       option.

       The log file is not compressed and can become  quite  large  if  rdiff-
       backup is run with high verbosity.


EXIT STATUS
       If  rdiff-backup  finishes successfully, the exit status will be 0.  If
       there is an unrecoverable (critical) error, it will be  non-zero  (usu-
       ally  1,  but  don't  depend  on this specific value).  When setting up
       rdiff-backup to run automatically (as from cron(8) or  similar)  it  is
       probably a good idea to check the exit code.


BUGS
       The  gzip  library  in versions 2.2 and earlier of python (but fixed in
       2.3a1) has trouble producing files over 2GB in length.  This  bug  will
       prevent  rdiff-backup from producing large compressed increments (snap-
       shots or diffs).  A workaround is  to  disable  compression  for  large
       uncompressable files.


AUTHOR
       Ben Escoto <ben@emerose.org>

       Feel  free to ask me questions or send me bug reports, but you may want
       to see the web page, mentioned below, first.


SEE ALSO
       python(1), rdiff(1), rsync(1), ssh(1).  The main rdiff-backup web  page
       is  at http://rdiff-backup.nongnu.org/.  It has more information, links
       to the mailing list and CVS, etc.























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