RDIFFDIR(1) User Manuals RDIFFDIR(1)


NAME
duplicity - Encrypted backup using rsync algorithm


SYNOPSIS
duplicity [options] source_directory target_url


duplicity [options] source_url target_directory


duplicity full [options] source_directory target_url


duplicity incremental [options] source_directory target_url


duplicity restore [options] source_url target_directory


duplicity verify [options] source_url target_directory


duplicity collection-status [options] target_url


duplicity list-current-files [options] target_url


duplicity cleanup [options] target_url


duplicity remove-older-than time [options] target_url


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


DESCRIPTION
Duplicity incrementally backs up files and directory by encrypting tar-format volumes with GnuPG and uploading them to a remote (or local) file
server. Currently local, ftp, ssh/scp, rsync, WebDAV, WebDAVs, HSi and Amazon S3 backends are available. Because duplicity uses librsync, the
incremental archives 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, directories, symbolic links, fifos, etc., but not hard links.


Duplicity will read the PASSPHRASE environment variable to find the passphrase to give to GnuPG. If this is not set, the user will be prompted for
the passphrase.


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 scp to back up /home/me to some_dir on the other.host machine:


duplicity /home/me scp://[email protected]/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 scp://[email protected]/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 scp://[email protected]/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 scp://[email protected]/some_dir /home/me/restored_file


The following command compares the files we backed up, so see what has changed since then:


duplicity verify scp://[email protected]/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://[email protected]/some_dir


ACTIONS
cleanup
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.


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


full Indicate full backup. If this is set, perform full backup even if signatures are available.


incr If this is requested an incremental backup will be performed. Duplicity will abort if old signatures cannot be found. The default is to
switch to full backup under these conditions.


list-current-files
Lists the files currently backed up in the archive. 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 may not detect it.


remove-older-than time
Delete all backup sets older than the given time. If 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.


remove-all-but-n-full count
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.


verify Enter verify mode instead of restore. If the --file-to-restore option is given, restrict verify to that file or directory. duplicity will
exit with a non-zero error level if any files are different. On verbosity level 4 or higher, log a message for each file that has changed.


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
When backing up or restoring, specify the local archive directory. This option is not necessary, but if hash data is found locally in path
it will be used in preference to the remote hash data. Use of this option does not imply that the archive data is no longer stored in the
backup destination, nor that the local archive directory need be kept safe. The local archive directory is a performance optimization only,
and may safely be discarded at any time.


--encrypt-key key
When backing up, encrypt to the given public key, instead of using symmetric (traditional) encryption. Can be specified multiple times.


--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. 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 information.


--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-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.


--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.


--gpg-options options
Allows you to pass options to gpg encryption. The options list should be of the form "opt1=parm1 opt2=parm2" 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-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-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.


--no-encryption
Do not use GnuPG to encrypt files on remote system. Instead just write gzipped volumes.

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


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


--scp-command command
This option only matters when using the ssh/scp backend. The command will be used instead of scp to send or receive files. The default is
"scp". To list and delete existing files, the sftp command is used. See --ssh-options and --sftp-command.


--sftp-command command
This option only matters when using the ssh/scp backend. The command will be used instead of sftp for listing and deleting files. The
default is "sftp". File transfers are done using the scp command. See --ssh-options and --scp-command.


--sign-key key
This option can be used when backing up or restoring. 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 keyid. key should be an 8 character hex string, like
AA0E73D2.


--ssh-askpass
Tells the ssh/scp backend to use FTP_PASSWORD from the environment, or, if that is not present, to prompt the user for the remote system
password.


--ssh-options options
Allows you to pass options to the ssh/scp/sftp 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 both scp and sftp, whose com-
mand line syntax differs slightly: options passed with --ssh-options should therefore be given in the long option format described in
ssh_config(5), like in this example:


duplicity --ssh-options="-oProtocol=2 -oIdentityFile=/my/backup/id" /home/me scp://[email protected]/some_dir


--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.


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


-ttime, --restore-time time
When restoring, specify the time to restore to.

-v[0-9], --verbosity [0-9]
Specify verbosity level (0 is total silent, 3 is the default, and 9 is noisiest).


--volsize number
Change the volume size to number Mb. Default is 5Mb.


URL FORMAT
Duplicity tries to maintain a standard URL format as much as possible. 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, how-
ever, it is permitted.


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


Formats of each of the URL schemes follow:


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


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


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


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


file:///some_dir


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


rsync://user[:password]@other.host[:port]/relative_path


rsync://user[:password]@other.host[:port]//absolute_path


s3://host/bucket_name[/prefix]


s3+http://bucket_name[/prefix]


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


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


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, 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 unsophisti-
cated: 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.


FILE SELECTION
duplicity accepts the same file selection options rdiff-backup does, including --exclude, --exclude-filelist-stdin, etc.


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-filelist-stdin, --exclude-globbing-filelist, --exclude-regexp, --include, --include-filelist,
--include-filelist-stdin, --include-globbing-filelist, 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.


For instance,


duplicity --include /usr --exclude /usr /usr scp://[email protected]/backup


is exactly the same as


duplicity /usr scp://[email protected]/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://[email protected]/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 patterns can
contain the special patterns *, **, ?, and [...]. 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 spe-
cial 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 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:


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 condi-
tions. 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 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 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 neither excludes nor includes /usr/local/man, leaving the fate of this directory to the next specification 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 interpreted
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 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.


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 duplic-
ity.


The files used by duplicity to store backup data are tarfiles in GNU tar format. They can be produced independently by rdiffdir(1). For incremen-
tal 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 "man-
ually" 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 unuseable.

In order to determine which files have been deleted, and to calculate diffs for changed files, duplicity needs to process information about previ-
ous 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. If
--archive-dir is used, 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


ENVIRONMENT VARIABLES
TMPDIR, TEMP, TMP
In decreasing order of importance, specifies the directory to use for temporary files (inherited from Python's tempfile module).


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.


AUTHOR
Original Author - Ben Escoto <[email protected]>


Current Maintainer - Kenneth Loafman <[email protected]>


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


Version 0.4.11 May 2008 RDIFFDIR(1)
(END)









Official page: http://duplicity.nongnu.org/index.html
Install guide for CentOS/Redhat: http://internetlifeforum.com/security-protection/1899-how-backup-remote-server-secure-like-rsync/