duplicity Man page

DUPLICITY(1) User Manuals DUPLICITY(1)

NAME

duplicity – Encrypted incremental backup to local or remote storage.

SYNOPSIS

For detailed descriptions for each command see chapter ACTIONS.

duplicity [full|incremental] [options] source_directory target_url

duplicity verify [options] [–compare-data] [–file-to-restore
] [–time time] source_url target_directory

duplicity collection-status [options] [–file-changed ] target_url

duplicity list-current-files [options] [–time time] target_url

duplicity [restore] [options] [–file-to-restore ] [–time
time] source_url target_directory

duplicity remove-older-than

duplicity remove-all-but-n-full [options] [–force] target_url

duplicity remove-all-inc-of-but-n-full [options] [–force] target_url

duplicity cleanup [options] [–force] [–extra-clean] target_url

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 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.

EXAMPLES
Here is an example of a backup, using sftp to back up /home/me to
some_dir on the other.host machine:

duplicity /home/me sftp://uid@other.host/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 sftp://uid@other.host/some_dir

or enforcing a full every other time via –full-if-older-than

duplicity –full-if-older-than 1M /home/me
sftp://uid@other.host/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 sftp://uid@other.host/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
sftp://uid@other.host/some_dir /home/me/restored_file

The following command compares the latest backup with the current
files:

duplicity verify sftp://uid@other.host/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://user@other.host/some_dir

ACTIONS
Duplicity knows action commands, which can be finetuned with options.
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.
If a backup is in order and old signatures can be found duplicity
automatically performs an incremental backup.

Note: The following explanations explain some but not all options that
can be used in connection with that action command. Consult the
OPTIONS section for more detailed informations.

full
Perform a full backup. A new backup chain is started even if
signatures are available for an incremental backup.

incr
If this is requested an incremental backup will be performed.
Duplicity will abort if no old signatures can be found.

verify [–compare-data] [–time

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

list-current-files [–time

restore [–file-to-restore ] [–time

remove-older-than

remove-all-but-n-full [–force]
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. Note that –force will be needed to delete
the files instead of just listing them.

remove-all-inc-of-but-n-full [–force]
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). 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 –force will be
needed to delete the files instead of just listing them.

cleanup [–force] [–extra-clean]
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 –force will
be needed to delete the files instead of just listing them.

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

1. neither specified (default)
~/.cache/duplicity/hash-of-url

2. –archive-dir=/arch, no –name
/arch/hash-of-url

3. no –archive-dir, –name=foo
~/.cache/duplicity/foo

4. –archive-dir=/arch, –name=foo
/arch/foo

–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.

–cf-backend backend
Allows the explicit selection of a cloudfiles backend. Defaults
to pyrax. Alternatively you might choose cloudfiles.

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

–dry-run
Calculate what would be done, but do not perform any backend
actions

–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 gpg, section “HOW TO SPECIFY A USER
ID” for details.

–encrypt-secret-keyring filename
This option can only be used with –encrypt-key, and changes the
path to the secret keyring for the encrypt key to 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

–encrypt-sign-key key-id
Convenience parameter. Same as –encrypt-key key-id –sign-key
key-id.

–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, with each line of the
filelist interpreted according to the same rules as –include
and –exclude. See the FILE SELECTION section for more
information.

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

–exclude-older-than time
Exclude any files whose modification date is earlier than the
specified time. This can be used to produce a partial backup
that contains only recently changed files. See the TIME FORMATS
section for more information.

–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.

–extra-clean
When cleaning up, be more aggressive about saving space. For
example, this may delete signature files for old backup chains.

Caution: Without signature files those old backup chains are
unrestorable. Do not use –extra-clean unless you know what
you’re doing.

See the cleanup argument for more information.

–file-changed path
This option may be given in collection-status mode, causing only
path status to be collect instead of the entire contents of the
backup archive. path should be given relative to the root of
the directory backed up.

–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 A NOTE ON FILENAME PREFIXES

–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.

–gio Use the GIO backend and interpret any URLs as GIO would.

–hidden-encrypt-key key-id
Same as –encrypt-key, but it hides user’s key id from encrypted
file. It uses the gpg’s –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 for more details.

–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.

–imap-full-address email_address
The full email address of the user name when logging into an
imap server. If not supplied just the user name part of the
email address is used.

–imap-mailbox option
Allows you to specify a different mailbox. The default is
“INBOX”. Other languages may require a different mailbox than
the default.

–gpg-binary file_path
Allows you to force duplicity to use file_path as gpg command
line binary. Can be an absolute or relative file path or a file
name. Default value is ‘gpg’. The binary will be localized via
the PATH environment variable.

–gpg-options options
Allows you to pass options to gpg encryption. The options list
should be of the form “–opt1 –opt2=parm” 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-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.

–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.

–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.

–max-blocksize number
determines the number of the blocks examined for changes during
the diff process. For files < 1MB the blocksize is a constant of 512. For files over 1MB the size is given by: file_blocksize = int((file_len / (2000 * 512)) * 512) return min(file_blocksize, globals.max_blocksize) where globals.max_blocksize defaults to 2048. If you specify a larger max_blocksize, your difftar files will be larger, but your sigtar files will be smaller. If you specify a smaller max_blocksize, the reverse occurs. The --max-blocksize option should be in multiples of 512. --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 --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. --no-compression Do not use GZip to compress files on remote system. --no-encryption Do not use GnuPG to encrypt files on remote system. --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 switches as well as the format of the directory statistics file. --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. --num-retries number Number of retries to make on errors before giving up. --old-filenames Use the old filename format (incompatible with Windows/Samba) rather than the new filename format. --par2-options options Verbatim options to pass to par2. --par2-redundancy percent Adjust the level of redundancy in percent for Par2 recovery files (default 10%). --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. --progress-rate number Sets the update rate at which duplicity will output the upload progress messages (requires --progress option). Default is to prompt the status each 3 seconds. --rename
Treats the path orig in the backup as if it were the path new.
Can be passed multiple times. An example:

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

–rsync-options options
Allows you to pass options to the rsync 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 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

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

–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.

–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.

–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.

–s3-use-ia
Store volumes using Standard – Infrequent Access when uploading
to Amazon S3. This storage class has a lower storage cost but a
higher per-request cost, and the storage cost is calculated
against a 30-day storage minimum. According to Amazon, this
storage is ideal for long-term file storage, backups, and
disaster recovery.

–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.

–s3-use-server-side-encryption
Allow use of server side encryption in S3

–s3-multipart-chunk-size
Chunk size (in MB) used for S3 multipart uploads. Make this
smaller than –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.

–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.

–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.

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

–sftp-command command
(only ssh pexpect backend) The command will be used instead of
“sftp”.
See also A NOTE ON SSH BACKENDS section SSH pexpect backend.

–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.

–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 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
given in any of the formats supported by GnuPG; see gpg,
section “HOW TO SPECIFY A USER ID” for details. Should be
specified only once because currently only one signing key is
supported. Last entry overrides all other entries.
See also A NOTE ON SYMMETRIC ENCRYPTION AND SIGNING

–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.

–ssh-options options
Allows you to pass options to the ssh backend. Can be specified
multiple times or as a space separated options list. The
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 ssh_config(5).

example of a list:

duplicity –ssh-options=”-oProtocol=2
-oIdentityFile=’/my/backup/id'” /home/me
scp://user@host/some_dir

example with multiple parameters:

duplicity –ssh-options=”-oProtocol=2″ –ssh-
options=”-oIdentityFile=’/my/backup/id'” /home/me
scp://user@host/some_dir

NOTE: The ssh paramiko backend currently supports only the -i or
-oIdentityFile setting. If needed provide more host specific
options via ssh_config file.

–ssl-cacert-file file
(only webdav backend) Provide a cacert file for ssl certificate
verification.
See also A NOTE ON SSL CERTIFICATE VERIFICATION.

–ssl-no-check-certificate
(only webdav backend) Disable ssl certificate verification.
See also A NOTE ON SSL CERTIFICATE VERIFICATION.

–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.
See also ENVIRONMENT VARIABLES.

-ttime, –time time, –restore-time time
Specify the time from which to restore or list files.

–time-separator char
Use char as the time separator in filenames instead of colon
(“:”).

–timeout seconds
Use seconds as the socket timeout value if duplicity begins to
timeout during network operations. The default is 30 seconds.

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

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

–version
Print duplicity’s version and quit.

–volsize number
Change the volume size to number Mb. Default is 25Mb.

ENVIRONMENT VARIABLES
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 –tempdir supercedes any of
these.

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).

PASSPHRASE
This passphrase is passed to GnuPG. If this is not set, the user
will be prompted for the passphrase.

SIGN_PASSPHRASE
The passphrase to be used for –sign-key. If ommitted and sign
key is also one of the keys to encrypt against PASSPHRASE will
be reused instead. Otherwise, if passphrase is needed but not
set the user will be prompted for it.

URL FORMAT
Duplicity uses the URL format (as standard as possible) to define data
locations. 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,
it is permitted however. Consider setting the environment variable
FTP_PASSWORD instead, which is used by most, if not all backends,
regardless of it’s name.

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.

Note:
Scheme (protocol) access may be provided by more than one
backend. In case the default backend is buggy or simply not
working in a specific case it might be worth trying an
alternative implementation. Alternative backends can be
selected by prefixing the scheme with the name of the
alternative backend e.g. ncftp+ftp:// and are mentioned below
the scheme’s syntax summary.

Formats of each of the URL schemes follow:

Azure

azure://container-name

See also A NOTE ON AZURE ACCESS

B2

b2://account_id[:application_key]@bucket_name/[folder/]

Cloud Files (Rackspace)

cf+http://container_name

See also A NOTE ON CLOUD FILES ACCESS

Copy cloud storage

copy://user[:password]@copy.com/some_dir

Dropbox

dpbx:///some_dir

Make sure to read A NOTE ON DROPBOX ACCESS first!

Local file path

file://[relative|/absolute]/local/path

FISH (Files transferred over Shell protocol) over ssh

fish://user[:pwd]@other.host[:port]/[relative|/absolute]_path

FTP

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

NOTE: use lftp+, ncftp+ prefixes to enforce a specific backend,
default is lftp+ftp://…

Google Docs

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

NOTE: use pydrive+, gdata+ prefixes to enforce a specific
backend, default is pydrive+gdocs://…

Google Cloud Storage

gs://bucket[/prefix]

HSI

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

hubiC

cf+hubic://container_name

See also A NOTE ON HUBIC

IMAP email storage

imap[s]://user[:password]@host.com[/from_address_prefix]

See also A NOTE ON IMAP

Mega cloud storage

mega://user[:password]@mega.co.nz/some_dir

OneDrive Backend

onedrive://some_dir

Par2 Wrapper Backend

par2+scheme://[user[:password]@]host[:port]/[/]path

See also A NOTE ON PAR2 WRAPPER BACKEND

Rsync via daemon

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

Rsync over ssh (only key auth)

rsync://user@host.com[:port]/[relative|/absolute]_path

S3 storage (Amazon)

s3://host/bucket_name[/prefix] s3+http://bucket_name[/prefix]

See also A NOTE ON EUROPEAN S3 BUCKETS

SCP/SFTP access

scp://.. or
sftp://user[:pwd]@other.host[:port]/[relative|/absolute]_path

defaults are paramiko+scp:// and paramiko+sftp://
alternatively try pexpect+scp://, pexpect+sftp://, lftp+sftp://
See also –ssh-askpass, –ssh-options and A NOTE ON SSH
BACKENDS.

Swift (Openstack)

swift://container_name

See also A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS

Tahoe-LAFS

tahoe://alias/directory

WebDAV

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

alternatively try lftp+webdav[s]://

pydrive

pydrive://@developer.gserviceaccount.com/some_dir

See also A NOTE ON PYDRIVE BACKEND below.

multi

multi:///path/to/config.json

See also A NOTE ON MULTI BACKEND below.

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 //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, –time, 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 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 time zone settings. For instance,
“2002/3/5”, “03-05-2002”, and “2002-3-05” all mean March 5th,
2002.

FILE SELECTION
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-regexp
–include
–include-filelist
–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://user@host/backup

is exactly the same as

duplicity /usr scp://user@host/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://user@host/backup

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

The include, exclude, include-filelist, and exclude-filelist options
accept some extended shell globbing patterns. These patterns can
contain *, **, ?, and […] (character ranges). 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 special 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 if:

1. pattern can be expanded into the file’s filename, or
2. the file is inside a directory matched by the option.

Conversely, the –include pattern matches a file if:

1. pattern can be expanded into the file’s filename, or
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 e.g. /usr/local, /usr/local/lib, and /usr/local/lib/netscape.
It is the same as –exclude /usr/local –exclude ‘/usr/local/**’.

On the other hand

–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 alone.

The –include-filelist, and –exclude-filelist, 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 the filelist will be interpreted as a globbing pattern the way
–include and –exclude options are interpreted, except that 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 would also include /usr/local/man, as
this is included within /user/local. Finally, it is undefined what
happens with /var. A single file list should not contain conflicting
file specifications.

Each line in the filelist will also be interpreted as a globbing
pattern the way –include and –exclude options are interpreted. For
instance, if the file “list.txt” contains the lines:

dir/foo
+ dir/bar
– **

Then –include-filelist 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 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
–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.

A NOTE ON AZURE ACCESS
The Azure backend requires the Microsoft Azure Storage SDK for Python
to be installed on the system. See REQUIREMENTS above.

It uses two environment variables for authentification:
AZURE_ACCOUNT_NAME (required), AZURE_ACCOUNT_KEY (required)

A container name must be a valid DNS name, conforming to the following
naming rules:

1. Container names must start with a letter or number, and
can contain only letters, numbers, and the dash (-)
character.

2. Every dash (-) character must be immediately preceded and
followed by a letter or number; consecutive dashes are
not permitted in container names.

3. All letters in a container name must be lowercase.

4. Container names must be from 3 through 63 characters
long.

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 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 REQUIREMENTS above.

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

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

A NOTE ON DROPBOX ACCESS
1. “some_dir” must already exist in the Dropbox Application folder
for this application, like “Apps/Duplicity/some_dir”.

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.

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.

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.

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
–s3-european-buckets was given. For reasons having to do with how the
Amazon S3 service works, this also requires the use of the –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.

Note that you will need to use –s3-use-new-style for all operations on
European buckets; not just upon initial creation.

You only need to use –s3-european-buckets upon initial creation, but
you may may use it at all times for consistency.

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.

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.

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
GS_ACCESS_KEY_ID and GS_SECRET_ACCESS_KEY environment variables.
Alternatively, you can run gsutil config -a to have the Google Cloud
Storage utility populate the ~/.boto configuration file.

Enable Interoperable Access:
//code.google.com/apis/console#:storage
Create Access Keys:
//code.google.com/apis/console#:storage:legacy

A NOTE ON HUBIC
The hubic backend requires the pyrax library to be installed on the
system. See REQUIREMENTS above. You will need to set your credentials
for hubiC in a file called ~/.hubic_credentials, following this
pattern:

[hubic] email = your_email
password = your_password
client_id = api_client_id
client_secret = api_secret_key
redirect_uri = http://localhost/

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.

The 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 from_address_prefix will distinguish
between different backups.

A NOTE ON MULTI BACKEND
The multi backend allows duplicity to combine the storage available in
more than one backend store (e.g., you can store across a google drive
account and a onedrive account to get effectively the combined storage
available in both). The URL path specifies a JSON formated config file
containing a list of the backends it will use. Multibackend then round-
robins across the given backends. Each element of the list must have a
“url” element, and may also contain an optional “description” and an
optional “env” list of environment variables used to configure that
backend.

For example:
[
{
“description”: “a comment about the backend”
“url”: “abackend://myuser@domain.com/backup”,
“env”: [
{
“name” : “MYENV”,
“value” : “xyz”
},
{
“name” : “FOO”,
“value” : “bar”
}
] },
{
“url”: “file:///path/to/dir”
}
]

A NOTE ON PAR2 WRAPPER BACKEND
Par2 Wrapper Backend can be used in combination with all other backends
to create recovery files. Just add par2+ before a regular scheme (e.g.
par2+ftp://user@host/dir or par2+s3+//bucket_name ). This will
create par2 recovery files for each archive and upload them all to the
wrapped backend.

Before restoring, archives will be verified. Corrupt archives will be
repaired on the fly if there are enough recovery blocks available.

Use –par2-redundancy percent to adjust the size (and redundancy) of
recovery files in percent.

A NOTE ON PYDRIVE BACKEND
The pydrive backend requires Python PyDrive package to be installed on
the system. See REQUIREMENTS above.

There are two ways to use PyDrive: with a regular account or with a
“service account”. With a service account, a separate account is
created, that is only accessible with Google APIs and not a web login.
With a regular account, you can store backups in your normal Google
Drive.

To use a service account, go to the Google developers console at
//console.developers.google.com. Create a project, and make sure
Drive API is enabled for the project. Under “APIs and auth”, click
Create New Client ID, then select Service Account with P12 key.

Download the .p12 key file of the account and convert it to the .pem
format:
openssl pkcs12 -in XXX.p12 -nodes -nocerts > pydriveprivatekey.pem

The content of .pem file should be passed to GOOGLE_DRIVE_ACCOUNT_KEY
environment variable for authentification.

The email address of the account will be used as part of URL. See URL
FORMAT above.

The alternative is to use a regular account. To do this, start as
above, but when creating a new Client ID, select “Installed
application” of type “Other”. Create a file with the following content,
and pass its filename in the GOOGLE_DRIVE_SETTINGS environment
variable:

client_config_backend: settings
client_config:
client_id:
client_secret:
save_credentials: True
save_credentials_backend: file
save_credentials_file:
get_refresh_token: True

In this scenario, the username and host parts of the URL play no role;
only the path matters. During the first run, you will be prompted to
visit an URL in your browser to grant access to your drive. Once
granted, you will receive a verification code to paste back into
Duplicity. The credentials are then cached in the file references above
for future use.

A NOTE ON SSH BACKENDS
The ssh backends support sftp and 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 sftp or scp/ssh access.
To make it even more confusing the user can choose between several ssh
backends via a scheme prefix: paramiko+ (default), pexpect+, lftp+… .
paramiko & pexpect support –use-scp, –ssh-askpass and –ssh-options.
Only the pexpect backend allows to define –scp-command and –sftp-
command.

SSH paramiko backend (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
REQUIREMENTS above. In sftp (default) mode all operations are done via
the according sftp commands. In scp mode ( –use-scp ) though scp
access is used for put/get operations but listing is done via ssh
remote shell.

SSH pexpect backend is the legacy ssh backend using the command line
ssh binaries via pexpect. Older versions used scp for get and put
operations and sftp for list and delete operations. The current
version uses sftp for all four supported operations, unless the –use-
scp option is used to revert to old behavior.

SSH lftp backend is simply there because lftp can interact with the ssh
cmd line binaries. It is meant as a last resort in case the above
options fail for some reason.

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.

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 PEM formatted text file as
currently provided by the CURL project. See

//curl.haxx.se/docs/caextract.html

After creating/retrieving a valid cacert file you should copy it to
either

~/.duplicity/cacert.pem
~/duplicity_cacert.pem
/etc/duplicity/cacert.pem

Duplicity searches it there in the same order and will fail if it can’t
find it. You can however specify the option –ssl-cacert-file
to point duplicity to a copy in a different location.

Finally there is the –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.

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

It uses four environment variables for authentification: SWIFT_USER

NAME

(required), SWIFT_PASSWORD (required), SWIFT_AUTHURL (required),
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: SWIFT_PREAUTHURL (required),
SWIFT_PREAUTHTOKEN (required)

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

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.

1. Setup gpg-agent properly. Use the option –use-agent and enter both
passphrases (symmetric and sign key) in the gpg-agent’s dialog.

2. Use a PASSPHRASE for symmetric encryption of your choice but the
signing key has an empty passphrase.

3. The used PASSPHRASE for symmetric encryption and the passphrase of
the signing key are identical.

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.

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 rdiffdir. 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 rdiff. 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 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
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 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. 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 –archive-dir ).

REQUIREMENTS
Duplicity requires a POSIX-like operating system with a 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):

azure backend (Azure Blob Storage Service)
Microsoft Azure Storage SDK for Python –
//pypi.python.org/pypi/azure-storage/

boto backend (S3 Amazon Web Services, Google Cloud Storage)
boto version 2.0+ – http://github.com/boto/boto

cfpyrax backend (Rackspace Cloud) and hubic backend (hubic.com)
Rackspace CloudFiles Pyrax API –
http://docs.rackspace.com/sdks/guide/content/python.html

dpbx backend (Dropbox)
Dropbox Python SDK –
https://www.dropbox.com/developers/reference/sdk

copy backend (Copy.com)
python-urllib3 – https://github.com/shazow/urllib3

gdocs gdata backend (legacy Google Docs backend)
Google Data APIs Python Client Library –
http://code.google.com/p/gdata-python-client/

gdocs pydrive backend(default)
see pydrive backend

gio backend (Gnome VFS API)
PyGObject – http://live.gnome.org/PyGObject
D-Bus (dbus)- http://www.freedesktop.org/wiki/Software/dbus

lftp backend (needed for ftp, ftps, fish [over ssh] – also supports
sftp, webdav[s])
LFTP Client – http://lftp.yar.ru/

mega backend (mega.co.nz)
Python library for mega API –
https://github.com/ckornacker/mega.py, ubuntu ppa –
ppa:ckornacker/backup

multi backend
Multi — store to more than one backend
(also see A NOTE ON MULTI BACKEND ) below.

ncftp backend (ftp, select via ncftp+ftp://)
NcFTP – http://www.ncftp.com/

OneDrive backend (Microsoft OneDrive)
python-requests – http://python-requests.org
python-requests-oauthlib – https://github.com/requests/requests-
oauthlib

Par2 Wrapper Backend
par2cmdline – http://parchive.sourceforge.net/

pydrive backend
PyDrive — a wrapper library of google-api-python-client –
https://pypi.python.org/pypi/PyDrive
(also see A NOTE ON PYDRIVE BACKEND ) below.

rsync backend
rsync client binary – http://rsync.samba.org/

ssh paramiko backend (default)
paramiko (SSH2 for python) –
http://pypi.python.org/pypi/paramiko (downloads);
http://github.com/paramiko/paramiko (project page)
pycrypto (Python Cryptography Toolkit) –
http://www.dlitz.net/software/pycrypto/

ssh pexpect backend
sftp/scp client binaries OpenSSH – http://www.openssh.com/
Python pexpect module –
http://pexpect.sourceforge.net/pexpect.html

swift backend (OpenStack Object Storage)
Python swiftclient module – https://github.com/openstack/python-
swiftclient/
Python keystoneclient module –
https://github.com/openstack/python-keystoneclient/

webdav backend
certificate authority database file for ssl certificate
verification of HTTPS connections –
http://curl.haxx.se/docs/caextract.html
(also see A NOTE ON SSL CERTIFICATE VERIFICATION).

AUTHOR

Original Author – Ben Escoto

Current Maintainer – Kenneth Loafman

Continuous Contributors
Edgar Soldin, Mike Terry

Most backends were contributed individually. Information about their
authorship may be found in the according file’s header.

Also we’d like to thank everybody posting issues 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.

A special thanks goes to rsync.net, a Cloud Storage provider with
explicit support for duplicity, for several monetary donations and for
providing a special “duplicity friends” rate for their offsite backup
service. Email info@rsync.net for details.

SEE ALSO

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

Version 0.7.06 December 07, 2015 DUPLICITY(1)