~ed.so/duplicity/lftp.ncftp.and.prefixes

.TH DUPLICITY 1 "$reldate" "Version $version" "User Manuals" \"  -*- nroff -*-
.\" disable justification (adjust text to left margin only)
.\" command line examples stay readable through that
.ad l
.\" disable hyphenation
.nh

.SH NAME
duplicity \- Encrypted incremental backup to local or remote storage.

.SH SYNOPSIS
For detailed descriptions for each command see chapter
.BR ACTIONS .

.B duplicity [full|incremental]
.I [options]
source_directory target_url

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

.B duplicity collection-status
.I [options]
target_url

.B duplicity list-current-files
.I [options] [--time time]
target_url

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

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

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

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

.B duplicity cleanup
.I [options] [--force] [--extra-clean]
target_url

.SH REQUIREMENTS
Duplicity requires a POSIX-like operating system with a
.B 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):
.TP
.BR "boto backend" " (S3 Amazon Web Services, Google Cloud Storage)"
.B boto version 2.0+
- http://github.com/boto/boto
.TP
.BR "cloudfiles backend (deprecated)" " (e.g. Rackspace Open Cloud)"
.B Cloud Files Python API (deprecated)
- http://www.rackspace.com/knowledge_center/article/python-api-installation-for-cloud-files
.TP
.BR "cfpyrax backend" " (Rackspace Cloud)"
.B Rackspace CloudFiles Pyrax API
- http://docs.rackspace.com/sdks/guide/content/python.html
.TP
.B "dpbx backend" (Dropbox)
.B Dropbox Python SDK
- https://www.dropbox.com/developers/reference/sdk
.TP
.B "copy backend" (Copy.com)
.B python-urllib3
- https://github.com/shazow/urllib3
.TP
.B "ftp backend"
.B NcFTP Client
- http://www.ncftp.com/
.TP
.B "ftps backend"
.B LFTP Client
- http://lftp.yar.ru/
.TP
.BR "gdocs backend" " (Google Docs)"
.B Google Data APIs Python Client Library
- http://code.google.com/p/gdata-python-client/
.TP
.BR "gio backend" " (Gnome VFS API)"
.B PyGObject
- http://live.gnome.org/PyGObject
.br
.B D-Bus
(dbus)- http://www.freedesktop.org/wiki/Software/dbus
.TP
.B "rsync backend"
.B rsync client binary
- http://rsync.samba.org/
.TP
.BR "mega backend" " (mega.co.nz)"
.B Python library for mega API
- https://github.com/ckornacker/mega.py, ubuntu ppa - ppa:ckornacker/backup
.TP
.B "Par2 Wrapper Backend"
.B par2cmdline
- http://parchive.sourceforge.net/
.PP
There are two
.B ssh backends
for scp/sftp/ssh access (also see
.BR "A NOTE ON SSH BACKENDS" ).
.TP
.BR "ssh paramiko backend" " (enabled by default)"
.B paramiko
(SSH2 for python)
- http://pypi.python.org/pypi/paramiko (downloads); http://github.com/paramiko/paramiko (project page)
.br
.B pycrypto
(Python Cryptography Toolkit)
- http://www.dlitz.net/software/pycrypto/
.TP
.B ssh pexpect backend
.B sftp/scp client binaries
OpenSSH - http://www.openssh.com/
.br
.B Python pexpect module
- http://pexpect.sourceforge.net/pexpect.html
.TP
.BR "swift backend (OpenStack Object Storage)"
.B Python swiftclient module
- https://github.com/openstack/python-swiftclient/
.br
.B Python keystoneclient module
- https://github.com/openstack/python-keystoneclient/
.TP
.B "webdav backend"
.B certificate authority database file
for ssl certificate verification of HTTPS connections
- http://curl.haxx.se/docs/caextract.html
.br
(also see
.BR "A NOTE ON SSL CERTIFICATE VERIFICATION" ).

.SH 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
.B 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.

.SH EXAMPLES
Here is an example of a backup, using sftp to back up /home/me to
some_dir on the other.host machine:
.PP
.RS
duplicity /home/me sftp://uid@other.host/some_dir
.PP
.RE
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
.I full
action:
.PP
.RS
duplicity full /home/me sftp://uid@other.host/some_dir
.PP
.RE
or enforcing a full every other time via
.I --full-if-older-than <time>
, e.g. a full every month:
.PP
.RS
duplicity --full-if-older-than 1M /home/me sftp://uid@other.host/some_dir
.PP
.RE
Now suppose we accidentally delete /home/me and want to restore it
the way it was at the time of last backup:
.PP
.RS
duplicity sftp://uid@other.host/some_dir /home/me
.PP
.RE
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:
.PP
.RS
duplicity -t 3D --file-to-restore Mail/article sftp://uid@other.host/some_dir /home/me/restored_file
.PP
.RE
The following command compares the latest backup with the current files:
.PP
.RS
duplicity verify sftp://uid@other.host/some_dir /home/me
.PP
.RE
Finally, duplicity recognizes several include/exclude options.  For
instance, the following will backup the root directory, but exclude
/mnt, /tmp, and /proc:
.PP
.RS
duplicity --exclude /mnt --exclude /tmp --exclude /proc /
file:///usr/local/backup
.PP
.RE
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:
.PP
.RS
duplicity --include /home --include /etc --exclude '**' /
file:///usr/local/backup
.PP
.RE
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:
.PP
.RS
FTP_PASSWORD=mypassword duplicity /local/dir ftp://user@other.host/some_dir

.SH ACTIONS
Duplicity knows action commands, which can be finetuned with options.
.br
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.
.br
If a backup is in order and old signatures can be found duplicity automatically
performs an incremental backup.
.PP
.B Note:
The following explanations explain some but
.B not
all options that can be used in connection with that action command.
Consult the OPTIONS section for more detailed informations.

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

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

.TP
.BI "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.
.br
The
.I --file-to-restore
option restricts verify to that file or folder.
The
.I --time
option allows to select a backup to verify against.
The
.I --compare-data
option enables data comparison (see below).

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

.TP
.BI "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.

.TP
.BI "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
.BR list-current-files .
Usually not needed as duplicity enters restore mode when it detects that the URL
comes before the local folder.

.TP
.BI "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
.I time
depend on them.  See the
.B TIME FORMATS
section for more information.  Note, this action cannot be combined
with backup or other actions, such as cleanup.  Note also that
.I --force
will be needed to delete the files instead of just listing them.

.TP
.BI "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
.I count
full backups and associated incremental sets).
.I count
must be larger than zero. A value of 1 means that only the single most
recent backup chain will be kept.  Note that
.I --force
will be needed to delete the files instead of just listing them.

.TP
.BI "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).
.I 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
.I --force
will be needed to delete the files instead of just listing them.

.TP
.BI "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
.I --force
will be needed to delete the files instead of just listing them.

.SH OPTIONS

.TP
.BI --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.

.TP
.BI "--archive-dir " path
The archive directory.
.B 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
.B 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
.IR path .
If the archive directory is not specified, the default will be to
create the archive directory in
.IR ~/.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
.B --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
.B --archive-dir
and the
.B --name
options allows for four possible combinations for the location of the archive dir:

.RS
.IP 1.
neither specified (default)
 ~/.cache/duplicity/\c
.IR hash-of-url
.IP 2.
--archive-dir=/arch, no --name
 /arch/\c
.IR hash-of-url
.IP 3.
no --archive-dir, --name=foo
 ~/.cache/duplicity/foo
.IP 4.
--archive-dir=/arch, --name=foo
 /arch/foo
.RE

.TP
.BI "--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.

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

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

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

.TP
.BI "--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
.BR gpg (1),
section "HOW TO SPECIFY A USER ID" for details.


.TP
.BI "--encrypt-secret-keyring " filename
This option can only be used with
.BR --encrypt-key ,
and changes the path to the secret keyring for the encrypt key to
.I 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

.TP
.BI "--encrypt-sign-key " key-id
Convenience parameter. Same as
.BR --encrypt-key
.IR key-id
.BR --sign-key
.IR "key-id" .

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

.TP
.B "--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.

.TP
.BI "--exclude-filelist " filename
Excludes the files listed in
.IR filename .
See the
.B FILE SELECTION
section for more information.

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

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

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

.TP
.B --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.

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

.TP
.B --extra-clean
When cleaning up, be more aggressive about saving space.  For example, this
may delete signature files for old backup chains.
See the
.B cleanup
argument for more information.

.TP
.BI "--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
.B "A NOTE ON FILENAME PREFIXES"

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

.TP
.BI "--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
.IR time .
See the
.B TIME FORMATS
section for more information.

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

.TP
.B --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.

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

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

.TP
.BI "--hidden-encrypt-key " key-id
Same as
.BR --encrypt-key ,
but it hides user's key id from encrypted file. It uses the gpg's
.B --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.


.TP
.B --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.

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

.TP
.BI "--gpg-options " options
Allows you to pass options to gpg encryption.  The
.I options
list should be of the form "opt1=parm1 opt2=parm2" where the string is
quoted and the only spaces allowed are between options.

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

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

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

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

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

.TP
.BI "--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.

.TP
.BI "--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.

.TP
.BI "--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
.B --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.

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

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

.TP
.B --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.

.TP
.B --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.

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

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

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

.TP
.B --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.

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

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

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

.TP
.BI "--rsync-options " options
Allows you to pass options to the rsync backend.  The
.I 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

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

.TP
.BI "--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.

.TP
.BI "--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.

.TP
.BI "--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.

.TP
.BI "--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.

.TP
.BI "--s3-multipart-chunk-size"
Chunk size (in MB) used for S3 multipart uploads. Make this smaller than
.B --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.

.TP
.BI "--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.

.TP
.BI "--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.


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

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

.TP
.BI --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.

.TP
.BI "--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
.IR 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 givein in any of
the formats supported by GnuPG; see
.BR gpg (1),
section "HOW TO SPECIFY A USER ID" for details.
Should be specified only once because currently only
.B one
signing key is supported. Last entry overrides all other entries.
.br
See also
.BI "A NOTE ON SYMMETRIC ENCRYPTION AND SIGNING"

.TP
.B --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.

.TP
.BI "--ssh-backend " backend
Allows the explicit selection of a ssh backend. Defaults to
.BR paramiko .
Alternatively you might choose
.BR pexpect .
.br
See also
.BR "A NOTE ON SSH BACKENDS" .

.TP
.BI "--ssh-options " options
Allows you to pass options to the ssh backend.  The
.I 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
.BR ssh_config(5) ,
like in this example:

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

.B NOTE:
.I ssh paramiko backend
currently supports only the
.B -oIdentityFile
setting.
.RE

.TP
.BI "--ssl-cacert-file " file
.B (only webdav backend)
Provide a cacert file for ssl certificate verification.
.br
See also
.BR "A NOTE ON SSL CERTIFICATE VERIFICATION" .

.TP
.B --ssl-no-check-certificate
.B (only webdav backend)
Disable ssl certificate verification.
.br
See also
.BR "A NOTE ON SSL CERTIFICATE VERIFICATION" .

.TP
.BI "--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.
.br
See also
.BR "ENVIRONMENT VARIABLES" .

.TP
.BI -t time ", --time " time ", --restore-time " time
Specify the time from which to restore or list files.

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

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

.TP
.BI --use-agent
If this option is specified, then
.I --use-agent
is passed to the GnuPG encryption process and it will try to connect to
.B gpg-agent
before it asks for a passphrase for
.I --encrypt-key
or
.I --sign-key
if needed.
.br
.B Note:
GnuPG 2 and newer ignore this option and will always use a running
.B gpg-agent
if no passphrase was delivered.

.TP
.BI --use-scp
If this option is specified, then the ssh backend will use the
scp protocol rather than sftp for backend operations.
.br
See also
.BR "A NOTE ON SSH BACKENDS" .

.TP
.BI "--verbosity " level ", -v" level
Specify output verbosity level (log level).
Named levels and corresponding values are
0 Error, 2 Warning, 4 Notice (default), 8 Info, 9 Debug (noisiest).
.br
.I level
may also be
.br
.B a character:
e, w, n, i, d
.br
.B 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.

.TP
.BI --version
Print duplicity's version and quit.

.TP
.BI "--volsize " number
Change the volume size to
.IR number
Mb. Default is 25Mb.

.SH ENVIRONMENT VARIABLES

.TP
.B 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
.B --tempdir
supercedes any of these.
.TP
.B 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).
.TP
.B PASSPHRASE
This passphrase is passed to GnuPG. If this is not set, the user will be
prompted for the passphrase.
.TP
.B SIGN_PASSPHRASE
The passphrase to be used for
.BR --sign-key .
If ommitted
.B and
sign key is also one of the keys to encrypt against
.B PASSPHRASE
will be reused instead.
Otherwise, if passphrase is needed but not set the user will be prompted for it.

.SH URL FORMAT
Duplicity uses the URL format (as standard as possible) to define data locations.
The generic format for a URL is:
.PP
.RS
scheme://[user[:password]@]host[:port]/[/]path
.PP
.RE
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
.B FTP_PASSWORD
instead, which is used by most, if not all backends, regardless of it's name.
.PP
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.
.PP
Formats of each of the URL schemes follow:
.RS
.PP
.BI "Rackspace Cloud Files"
.br
cf+http://container_name
.br
See also
.B "A NOTE ON CLOUD FILES ACCESS"
.PP
.BI Dropbox
.br
dpbx:///some_dir
.br
Make sure to read
.BR "A NOTE ON DROPBOX ACCESS" " first!"
.PP
copy://user[:password]@copy.com/some_dir
.PP
.PP
file://[relative|/absolute]/local/path
.PP
ftp[s]://user[:password]@other.host[:port]/some_dir
.PP
gdocs://user[:password]@other.host/some_dir
.PP
.BI "Google Cloud Storage"
.br
gs://bucket[/prefix]
.PP
hsi://user[:password]@other.host/some_dir
.PP
imap[s]://user[:password]@host.com[/from_address_prefix]
.br
See also
.B "A NOTE ON IMAP"
.PP
mega://user[:password]@mega.co.nz/some_dir
.PP
.BI "Par2 Wrapper Backend"
.br
par2+scheme://[user[:password]@]host[:port]/[/]path
.br
See also
.B "A NOTE ON PAR2 WRAPPER BACKEND"
.PP
.B "using rsync daemon"
.br
rsync://user[:password]@host.com[:port]::[/]module/some_dir
.br
.B "using rsync over ssh (only key auth)"
.br
rsync://user@host.com[:port]/[relative|/absolute]_path
.PP
s3://host/bucket_name[/prefix]
.br
s3+http://bucket_name[/prefix]
.br
See also
.B "A NOTE ON EUROPEAN S3 BUCKETS"
.PP
scp://.. or ssh://.. are synonymous with
.br
sftp://user[:password]@other.host[:port]/[/]some_dir
.br
See also
.BR --ssh-backend ,
.BR --ssh-askpass ,
.BR --use-scp ,
.B  --ssh-options
and
.BR "A NOTE ON SSH BACKENDS" .
.PP
swift://container_name
.br
See also
.B "A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS"
.PP
tahoe://alias/directory
.PP
webdav[s]://user[:password]@other.host[:port]/some_dir
.RE

.SH 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.
.PP
Secondly, the
.BR -t ", " --time ", and " --restore-time
options take a time string, which can be given in any of several
formats:
.IP 1.
the string "now" (refers to the current time)
.IP 2.
a sequences of digits, like "123456890" (indicating the time in
seconds after the epoch)
.IP 3.
A string like "2002-01-25T07:00:00+02:00" in datetime format
.IP 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.
.IP 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.

.SH FILE SELECTION
duplicity accepts the same file selection options
.B 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:
.RS
--exclude
.br
--exclude-device-files
.br
--exclude-filelist
.br
--exclude-filelist-stdin
.br
--exclude-globbing-filelist
.br
--exclude-regexp
.br
--include
.br
--include-filelist
.br
--include-filelist-stdin
.br
--include-globbing-filelist
.br
--include-regexp
.RE
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,
.PP
.RS
duplicity --include /usr --exclude /usr /usr scp://user@host/backup
.PP
.RE
is exactly the same as
.PP
.RS
duplicity /usr scp://user@host/backup
.PP
.RE
because the include and exclude directives match exactly the same
files, and the
.B --include
comes first, giving it precedence.  Similarly,
.PP
.RS
duplicity --include /usr/local/bin --exclude /usr/local /usr
scp://user@host/backup
.PP
.RE
would backup the /usr/local/bin directory (and its contents), but not
/usr/local/doc.

The
.BR include ,
.BR exclude ,
.BR include-globbing-filelist ,
and
.B exclude-globbing-filelist
options accept some
.IR "extended shell globbing patterns" .
These patterns can contain
.BR * ,
.BR ** ,
.BR ? ,
and
.B [...]
(character ranges). As in a normal shell,
.B *
can be expanded to any string of characters not containing "/",
.B ?
expands to any character except "/", and
.B [...]
expands to a single character of those characters specified (ranges
are acceptable).  The new special pattern,
.BR ** ,
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
.B --exclude
pattern option matches a file if:
.PP
.B 1.
.I pattern
can be expanded into the file's filename, or
.br
.B 2.
the file is inside a directory matched by the option.
.PP
Conversely, the
.B "--include "
pattern matches a file if:
.PP
.B 1.
.I pattern
can be expanded into the file's filename, or
.br
.B 2.
the file is inside a directory matched by the option, or
.br
.B 3.
the file is a directory which contains a file matched by the option.
.PP
For example,

.RS
.B --exclude
/usr/local
.RE

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

.RS
.B --include
/usr/local
.RE

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.
.PP
Finally,

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

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
.BR --include-filelist ,
.BR --exclude-filelist ,
.BR --include-filelist-stdin ,
and
.B --exclude-filelist-stdin
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 a filelist is
interpreted similarly to the way
.I extended shell patterns
are, with a few exceptions:
.PP
.B 1.
Globbing patterns like
.BR * ,
.BR ** ,
.BR ? ,
and
.B [...]
are not expanded.
.br
.B 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.
.br
.B 3.
Lines starting with "+ " are interpreted as include directives, even
if found in a filelist referenced by
.BR --exclude-filelist .
Similarly, lines starting with "- " exclude files even if they are
found within an include filelist.
.PP
For example, if file "list.txt" contains the lines:

.RS
/usr/local
.br
- /usr/local/doc
.br
/usr/local/bin
.br
+ /var
.br
- /var
.RE

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

.RS
dir/foo
.br
+ dir/bar
.br
- **
.RE

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

Finally, the
.B --include-regexp
and
.B --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
.B --include
and
.B --exclude
options, the regular expression options don't match files containing
or contained in matched files.  So for instance
.PP
.RS
--include '[0-9]{7}(?!foo)'
.PP
.RE
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.

.SH 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
.B 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
.B REQUIREMENTS
above.

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

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

.SH A NOTE ON DROPBOX ACCESS
.IP 1.
"some_dir" must already exist in the Dropbox Application folder for
this application, like "Apps/Duplicity/some_dir".
.IP 2.
The first run of the backend must be ineractive!
It will print the URL that you need to open in the browser to obtain
OAuth token for the application. The token will be saved in the file
$HOME/.dropbox.token_store.txt and used in the future runs.
.IP 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.

.SH 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.
.PP
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
.B --s3-european-buckets
was given. For reasons having to do with how the Amazon S3 service
works, this also requires the use of the
.B --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.
.PP
Note that you will need to use
.B --s3-use-new-style
for all operations on European buckets; not just upon initial
creation.
.PP
You only need to use
.B --s3-european-buckets
upon initial creation, but you may may use it at all times for
consistency.
.PP
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.

.SH 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
.B GS_ACCESS_KEY_ID
and
.B GS_SECRET_ACCESS_KEY
environment variables. Alternatively, you can run
.B "gsutil config -a"
to have the Google Cloud Storage utility populate the
.B ~/.boto
configuration file.
.PP
Enable Interoperable Access:
https://code.google.com/apis/console#:storage
.br
Create Access Keys:
https://code.google.com/apis/console#:storage:legacy

.SH 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.
.PP
The
.B 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
.B from_address_prefix
will distinguish between different backups.

.SH A NOTE ON PAR2 WRAPPER BACKEND
Par2 Wrapper Backend can be used in combination with all other backends to
create recovery files. Just add
.BR par2+
before a regular scheme (e.g.
.IR par2+ftp://user@host/dir " or"
.I par2+s3+http://bucket_name
). This will create par2 recovery files for each archive and upload them all to
the wrapped backend.
.PP
Before restoring, archives will be verified. Corrupt archives will be repaired
on the fly if there are enough recovery blocks available.
.PP
Use
.BI "--par2-redundancy " percent
to adjust the size (and redundancy) of recovery files in
.I percent.

.SH A NOTE ON SSH BACKENDS
The
.I ssh backends
support
.I sftp
and
.I 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
.IR sftp " or"
.I scp/ssh
access.
To make it even more confusing the user can choose between two ssh backends via
.BR --ssh-backend " option."
.br
Both support
.BR --use-scp ,
.BR --ssh-askpass " and"
.BR --ssh-options "."
Only the
.B pexpect
backend allows to define
.BR --scp-command " and"
.BR --sftp-command .
.PP
.BR "SSH paramiko backend " "(selected by 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
.B REQUIREMENTS
above. In
.I sftp
(default) mode all operations are done via the according sftp commands. In
.I scp
mode (
.I --use-scp
) though scp access is used for put/get operations but listing is done via ssh remote shell.
.PP
.B SSH pexpect backend
is the legacy ssh backend using the command line ssh binaries via pexpect.
Older versions used
.I scp
for get and put operations and
.I sftp
for list and
delete operations.  The current version uses
.I sftp
for all four supported
operations, unless the
.I --use-scp
option is used to revert to old behavior.
.PP
.B 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.

.SH A NOTE ON SSL CERTIFICATE VERIFICATION
Certificate verification as implemented right now [01.2013] only in the webdav backend needs a file
based database of certification authority certificates (cacert file). It has to be a
.B PEM
formatted text file as currently provided by the
.B CURL
project. See
.PP
.RS
http://curl.haxx.se/docs/caextract.html
.PP
.RE
After creating/retrieving a valid cacert file you should copy it to either
.PP
.RS
~/.duplicity/cacert.pem
.br
~/duplicity_cacert.pem
.br
/etc/duplicity/cacert.pem
.PP
.RE
Duplicity searches it there in the same order and will fail if it can't find it.
You can however specify the option
.BI --ssl-cacert-file " <file>"
to point duplicity to a copy in a different location.
.PP
Finally there is the
.B --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.

.SH A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS
Swift is the OpenStack Object Storage service.
.br
The backend requires python-switclient to be installed on the system.
python-keystoneclient is also needed to use OpenStack's Keystone Identity service.
See
.B REQUIREMENTS
above.

It uses four environment variables for authentification:
.BR SWIFT_USERNAME " (required),"
.BR SWIFT_PASSWORD " (required),"
.BR SWIFT_AUTHURL " (required),"
.BR 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:
.BR SWIFT_PREAUTHURL " (required),"
.BR SWIFT_PREAUTHTOKEN " (required)"

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

.SH 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.
.PP
1. Setup gpg-agent properly. Use the option
.BI --use-agent
and enter both passphrases (symmetric and sign key) in the gpg-agent's dialog.
.PP
2. Use a
.BI PASSPHRASE
for symmetric encryption of your choice but the signing key has an
.B empty
passphrase.
.PP
3. The used
.BI PASSPHRASE
for symmetric encryption and the passphrase of the signing key are identical.

.SH 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.

.SH 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.

.SH 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
.BR 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
.BR 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
.B tar
and then
.BR cp ,
.BR rdiff ,
and
.B rm
as necessary.  These duplicity archives have the extension
.BR 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
.B duplicity-full
while the incremental sets start with
.BR 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
.BR rdiff )
of the file instead of the file's contents.  These signature sets have
the extension
.BR 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
.B duplicity-full-signatures
and
.B 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
.B "--archive-dir"
).

.SH AUTHOR
.TP
.BR "Original Author" " - Ben Escoto <bescoto@stanford.edu>"
.TP
.BR "Current Maintainer" " - Kenneth Loafman <kenneth@loafman.com>"
.br
.TP
.B "Continuous Contributors"
Edgar Soldin, Mike Terry
.PP
Most backends were contributed individually.
Information about their authorship may be found in the according file's header.
.br
Also we'd like to thank everybody posting issue 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.

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