Table of Contents
duplicity - Encrypted incremental backup to local or remote storage.
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 <relpath>] [--time time] source_url
target_directory
duplicity collection-status [options] target_url
duplicity
list-current-files [options] [--time time] target_url
duplicity [restore]
[options] [--file-to-restore <relpath>] [--time time] source_url target_directory
duplicity remove-older-than <time> [options] [--force] target_url
duplicity
remove-all-but-n-full <count> [options] [--force] target_url
duplicity remove-all-inc-of-but-n-full
<count> [options] [--force] target_url
duplicity cleanup [options] [--force]
[--extra-clean] target_url
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):
- boto backend (S3 Amazon
Web Services, Google Cloud Storage)
- boto version 2.0+ - http://github.com/boto/boto
- cloudfiles backend (deprecated) (e.g. Rackspace Open Cloud)
- Cloud Files Python
API (deprecated) - http://www.rackspace.com/knowledge_center/article/python-api-installation-for-cloud-files
- cfpyrax backend (Rackspace Cloud)
- 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
- ftp backend
- NcFTP Client - http://www.ncftp.com/
- ftps backend
- LFTP Client
- http://lftp.yar.ru/
- gdocs backend (Google Docs)
- Google Data APIs Python
Client Library - http://code.google.com/p/gdata-python-client/
- gio backend (Gnome
VFS API)
- PyGObject - http://live.gnome.org/PyGObject
D-Bus (dbus)- http://www.freedesktop.org/wiki/Software/dbus
- rsync backend
- rsync
client binary - http://rsync.samba.org/
- mega backend (mega.co.nz)
- Python library
for mega API - https://github.com/ckornacker/mega.py,
ubuntu ppa - ppa:ckornacker/backup
- Par2 Wrapper Backend
- par2cmdline - http://parchive.sourceforge.net/
There
are two ssh backends for scp/sftp/ssh access (also see A NOTE ON SSH BACKENDS).
- ssh paramiko backend (enabled by 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).
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.
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 <time> , e.g. a full every month:
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
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
<folder> <url>
- Perform a full backup. A new backup chain is started even if
signatures are available for an incremental backup.
- incr <folder> <url>
- If
this is requested an incremental backup will be performed. Duplicity will
abort if no old signatures can be found.
- 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.
The --file-to-restore option restricts verify to that file or folder. The --time
option allows to select a backup to verify against. The --compare-data option
enables data comparison (see below).
- collection-status <url>
- 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 <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.
- 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 list-current-files. Usually
not needed as duplicity enters restore mode when it detects that the URL
comes before the local folder.
- 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 time depend on them. See the TIME FORMATS
section for more information. Note, this action cannot be combined with
backup or other actions, such as cleanup. Note also that --force will be
needed to delete the files instead of just listing them.
- 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 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 <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). 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] <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 --force will be needed to delete the files instead of just listing
them.
- --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(1)
, 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. See the FILE SELECTION section
for more information.
- --exclude-filelist-stdin
- Like --exclude-filelist, but the
list of files will be read from standard input. See the FILE SELECTION
section for more information.
- --exclude-globbing-filelist filename
- Like --exclude-filelist
but each line of the filelist will be interpreted according to the same
rules as --include and --exclude.
- --exclude-if-present filename
- Exclude directories
if filename is present. This option needs to come before any other include
or exclude options.
- --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. See the
cleanup argument for more information.
- --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(1)
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-mailbox
option
- Allows you to specify a different mailbox. The default is "INBOX".
Other languages may require a different mailbox than the default.
- --gpg-options
options
- Allows you to pass options to gpg encryption. The options list
should be of the form "opt1=parm1 opt2=parm2" where the string is quoted
and the only spaces allowed are between options.
- --include shell_pattern
- Similar to --exclude but include matched files instead. Unlike --exclude, this
option will also match parent directories of matched files (although not
necessarily their contents). See the FILE SELECTION section for more information.
- --include-filelist filename
- Like --exclude-filelist, but include the listed
files instead. See the FILE SELECTION section for more information.
- --include-filelist-stdin
- Like --include-filelist, but read the list of included files from standard
input.
- --include-globbing-filelist filename
- Like --include-filelist but each line
of the filelist will be interpreted according to the same rules as --include
and --exclude.
- --include-regexp regexp
- Include files matching the regular expression
regexp. Only files explicitly matched by regexp will be included by this
option. See the FILE SELECTION section for more information.
- --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-encryption
- Do not use
GnuPG to encrypt files on remote system. Instead just write gzipped volumes.
- --no-print-statistics
- By default duplicity will print statistics about the
current session after a successful backup. This switch disables that behavior.
- --null-separator
- Use nulls (\0) instead of newlines (\n) as line separators,
which may help when dealing with filenames containing newlines. This affects
the expected format of the files specified by the --{include|exclude}-filelist[-stdin]
switches as well as the format of the directory statistics file.
- --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-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 <original path> <new path>
- 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-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-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 givein in any of the formats supported by
GnuPG; see gpg(1)
, 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-backend backend
- Allows
the explicit selection of a ssh backend. Defaults to paramiko. Alternatively
you might choose pexpect.
See also A NOTE ON SSH BACKENDS.
- --ssh-options options
- Allows you to pass
options to the ssh backend. 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)
,
like in this example:
duplicity --ssh-options="-oProtocol=2 -oIdentityFile=/my/backup/id"
/home/me scp://uid@other.host/some_dir
NOTE: ssh paramiko backend currently
supports only the -oIdentityFile setting.
- --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.
- --use-scp
- If this option is specified,
then the ssh backend will use the scp protocol rather than sftp for backend
operations.
See also A NOTE ON SSH BACKENDS.
- --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/-vNotice and -vNOTICE.
- --version
- Print duplicity’s version and quit.
- --volsize number
- Change the volume size
to number Mb. Default is 25Mb.
- 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.
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.
Formats of each of the URL schemes follow:
Rackspace Cloud Files
cf+http://container_name
See also A NOTE ON CLOUD FILES ACCESS
Dropbox
dpbx:///some_dir
Make sure to read A NOTE ON DROPBOX ACCESS first!
copy://user[:password]@copy.com/some_dir
file://[relative|/absolute]/local/path
ftp[s]://user[:password]@other.host[:port]/some_dir
gdocs://user[:password]@other.host/some_dir
Google Cloud Storage
gs://bucket[/prefix]
hsi://user[:password]@other.host/some_dir
imap[s]://user[:password]@host.com[/from_address_prefix]
See also A NOTE ON IMAP
mega://user[:password]@mega.co.nz/some_dir
Par2 Wrapper
Backend
par2+scheme://[user[:password]@]host[:port]/[/]path
See also A NOTE ON PAR2 WRAPPER BACKEND
using rsync daemon
rsync://user[:password]@host.com[:port]::[/]module/some_dir
using rsync over ssh (only key auth)
rsync://user@host.com[:port]/[relative|/absolute]_path
s3://host/bucket_name[/prefix]
s3+http://bucket_name[/prefix]
See also A NOTE ON EUROPEAN S3 BUCKETS
scp://.. or ssh://.. are synonymous
with
sftp://user[:password]@other.host[:port]/[/]some_dir
See also --ssh-backend, --ssh-askpass, --use-scp, --ssh-options and A NOTE ON SSH BACKENDS.
swift://container_name
See also A NOTE ON SWIFT (OPENSTACK OBJECT STORAGE) ACCESS
tahoe://alias/directory
webdav[s]://user[:password]@other.host[:port]/some_dir
duplicity
uses time strings in two places. Firstly, many of the files duplicity creates
will have the time in their filenames in the w3 datetime format as described
in a w3 note at http://www.w3.org/TR/NOTE-datetime.
Basically they look like
"2001-07-15T04:09:38-07:00", which means what it looks like. The "-07:00" section
means the time zone is 7 hours behind UTC.
Secondly, the -t, --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.
duplicity
accepts the same file selection options rdiff-backup does, including --exclude,
--exclude-filelist-stdin, etc.
When duplicity is run, it searches through the
given source directory and backs up all the files specified by the file
selection system. The file selection system comprises a number of file
selection conditions, which are set using one of the following command
line options:
--exclude
--exclude-device-files
--exclude-filelist
--exclude-filelist-stdin
--exclude-globbing-filelist
--exclude-regexp
--include
--include-filelist
--include-filelist-stdin
--include-globbing-filelist
--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-globbing-filelist, and exclude-globbing-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, --exclude-filelist, --include-filelist-stdin,
and --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 extended shell patterns are, with a few exceptions:
1. Globbing patterns
like *, **, ?, and [...] are not expanded.
2. Include patterns do not match files in a directory that is included. So
/usr/local in an include file will not match /usr/local/doc.
3. Lines starting with "+ " are interpreted as include directives, even
if found in a filelist referenced by --exclude-filelist. Similarly, lines starting
with "- " exclude files even if they are found within an include filelist.
For example, if file "list.txt" contains the lines:
/usr/local
- /usr/local/doc
/usr/local/bin
+ /var
- /var
then --include-filelist list.txt would include /usr, /usr/local, and
/usr/local/bin. It would exclude /usr/local/doc, /usr/local/doc/python,
etc. It neither excludes nor includes /usr/local/man, leaving the fate
of this directory to the next specification condition. Finally, it is undefined
what happens with /var. A single file list should not contain conflicting
file specifications.
The --include-globbing-filelist and --exclude-globbing-filelist
options also specify filelists, but each line in the filelist will be interpreted
as a globbing pattern the way --include and --exclude options are interpreted
(although "+ " and "- " prefixing is still allowed). For instance, if the
file "globbing-list.txt" contains the lines:
dir/foo
+ dir/bar
- **
Then --include-globbing-filelist globbing-list.txt would be exactly the
same as specifying --include dir/foo --include dir/bar --exclude ** on the command
line.
Finally, the --include-regexp and --exclude-regexp 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.
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.
- 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.
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.
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.
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: https://code.google.com/apis/console#:storage
Create Access Keys: https://code.google.com/apis/console#:storage:legacy
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.
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+http://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.
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 two ssh backends via --ssh-backend option.
Both support --use-scp, --ssh-askpass and --ssh-options. Only the pexpect backend
allows to define --scp-command and --sftp-command.
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 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.
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.
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
http://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
<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.
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_USERNAME
(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.
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.
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.
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(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 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 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 ).
- Original Author - Ben Escoto <bescoto@stanford.edu>
- Current Maintainer - Kenneth Loafman <kenneth@loafman.com>
- 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 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.
rdiffdir(1)
, python(1)
,
rdiff(1)
, rdiff-backup(1)
.
Table of Contents