bup-restore man page

bup-restore — extract files from a backup set

Synopsis

bup restore [--outdir=outdir] [--exclude-rx pattern] [--exclude-rx-from filename] [-v] [-q] <paths...>

Description

bup restore extracts files from a backup set (created with bup-save(1)) to the local filesystem.

The specified paths are of the form /branch/revision/some/where. The components of the path are as follows:

branch
the name of the backup set to restore from; this corresponds to the --name (-n) option to bup save.
revision
the revision of the backup set to restore. The revision latest is always the most recent backup on the given branch. You can discover other revisions using bup ls /branch.
some/where
the previously saved path (after any stripping/grafting) that you want to restore. For example, etc/passwd.

If some/where names a directory, bup restore will restore that directory and then recursively restore its contents.

If some/where names a directory and ends with a slash (ie. path/to/dir/), bup restore will restore the children of that directory directly to the current directory (or the --outdir). If some/where does not end in a slash, the children will be restored to a subdirectory of the current directory.

If some/where names a directory and ends in '/.' (ie. path/to/dir/.), bup restore will do exactly what it would have done for path/to/dir, and then restore dir's metadata to the current directory (or the --outdir). See the Examples section.

Whenever path metadata is available, bup restore will attempt to restore it. When restoring ownership, bup implements tar/rsync-like semantics. It will normally prefer user and group names to uids and gids when they're available, but it will not try to restore the user unless running as root, and it will fall back to the numeric uid or gid whenever the metadata contains a user or group name that doesn't exist on the current system. The use of user and group names can be disabled via --numeric-ids (which can be important when restoring a chroot, for example), and as a special case, a uid or gid of 0 will never be remapped by name. Additionally, some systems don't allow setting a uid/gid that doesn't correspond with a known user/group. On those systems, bup will log an error for each relevant path.

The --map-user, --map-group, --map-uid, --map-gid options may be used to adjust the available ownership information before any of the rules above are applied, but note that due to those rules, --map-uid and --map-gid will have no effect whenever a path has a valid user or group. In those cases, either --numeric-ids must be specified, or the user or group must be cleared by a suitable --map-user foo= or --map-group foo=.

Hardlinks will also be restored when possible, but at least currently, no links will be made to targets outside the restore tree, and if the restore tree spans a different arrangement of filesystems from the save tree, some hardlink sets may not be completely restored.

Also note that changing hardlink sets on disk between index and save may produce unexpected results. With the current implementation, bup will attempt to recreate any given hardlink set as it existed at index time, even if all of the files in the set weren't still hardlinked (but were otherwise identical) at save time.

Note that during the restoration process, access to data within the restore tree may be more permissive than it was in the original source. Unless security is irrelevant, you must restore to a private subdirectory, and then move the resulting tree to its final position. See the Examples section for a demonstration.

Options

-C, --outdir=outdir
create and change to directory outdir before extracting the files.
--numeric-ids
restore numeric IDs (user, group, etc.) rather than names.
--exclude-rx=pattern

exclude any path matching pattern, which must be a Python regular expression (http://docs.python.org/library/re.html). The pattern will be compared against the full path rooted at the top of the restore tree, without anchoring, so "x/y" will match "ox/yard" or "box/yards". To exclude the contents of /tmp, but not the directory itself, use "^/tmp/.". (can be specified more than once)

Note that the root of the restore tree (which matches '^/') is the top of the archive tree being restored, and has nothing to do with the filesystem destination. Given "restore ... /foo/latest/etc/", the pattern '^/passwd$' would match if a file named passwd had been saved as '/foo/latest/etc/passwd'.

Examples:

·
'/foo$' - exclude any file named foo
·
'/foo/$' - exclude any directory named foo
·
'/foo/.' - exclude the content of any directory named foo
·
'^/tmp/.' - exclude root-level /tmp's content, but not /tmp itself
--exclude-rx-from=filename
read --exclude-rx patterns from filename, one pattern per-line (may be repeated). Ignore completely empty lines.
--sparse
write output data sparsely when reasonable. Currently, reasonable just means "at least whenever there are 512 or more consecutive zeroes".
--map-user old=new
for every path, restore the old (saved) user name as new. Specifying "" for new will clear the user. For example "--map-user foo=" will allow the uid to take effect for any path that originally had a user of "foo", unless countermanded by a subsequent "--map-user foo=..." specification. See Description above for further information.
--map-group old=new
for every path, restore the old (saved) group name as new. Specifying "" for new will clear the group. For example "--map-group foo=" will allow the gid to take effect for any path that originally had a group of "foo", unless countermanded by a subsequent "--map-group foo=..." specification. See Description above for further information.
--map-uid old=new
for every path, restore the old (saved) uid as new, unless countermanded by a subsequent "--map-uid old=..." option. Note that the uid will only be relevant for paths with no user. See Description above for further information.
--map-gid old=new
for every path, restore the old (saved) gid as new, unless countermanded by a subsequent "--map-gid old=..." option. Note that the gid will only be relevant for paths with no user. See Description above for further information.
-v, --verbose
increase log output. Given once, prints every directory as it is restored; given twice, prints every file and directory.
-q, --quiet
don't show the progress meter. Normally, is stderr is a tty, a progress display is printed that shows the total number of files restored.

Examples

Create a simple test backup set:

$ bup index -u /etc
$ bup save -n mybackup /etc/passwd /etc/profile

Restore just one file:

$ bup restore /mybackup/latest/etc/passwd
Restoring: 1, done.

$ ls -l passwd
-rw-r--r-- 1 apenwarr apenwarr 1478 2010-09-08 03:06 passwd

Restore etc to test (no trailing slash):

$ bup restore -C test /mybackup/latest/etc
Restoring: 3, done.

$ find test
test
test/etc
test/etc/passwd
test/etc/profile

Restore the contents of etc to test (trailing slash):

$ bup restore -C test /mybackup/latest/etc/
Restoring: 2, done.

$ find test
test
test/passwd
test/profile

Restore the contents of etc and etc's metadata to test (trailing "/."):

$ bup restore -C test /mybackup/latest/etc/.
Restoring: 2, done.

# At this point test and etc's metadata will match.
$ find test
test
test/passwd
test/profile

Restore a tree without risk of unauthorized access:

# mkdir --mode 0700 restore-tmp

# bup restore -C restore-tmp /somebackup/latest/foo
Restoring: 42, done.

# mv restore-tmp/foo somewhere

# rmdir restore-tmp

Restore a tree, remapping an old user and group to a new user and group:

# ls -l /original/y
-rw-r----- 1 foo baz  3610 Nov  4 11:31 y
# bup restore -C dest --map-user foo=bar --map-group baz=bax /x/latest/y
Restoring: 42, done.
# ls -l dest/y
-rw-r----- 1 bar bax  3610 Nov  4 11:31 y

Restore a tree, remapping an old uid to a new uid. Note that the old user must be erased so that bup won't prefer it over the uid:

# ls -l /original/y
-rw-r----- 1 foo baz  3610 Nov  4 11:31 y
# ls -ln /original/y
-rw-r----- 1 1000 1007  3610 Nov  4 11:31 y
# bup restore -C dest --map-user foo= --map-uid 1000=1042 /x/latest/y
Restoring: 97, done.
# ls -ln dest/y
-rw-r----- 1 1042 1007  3610 Nov  4 11:31 y

An alternate way to do the same by quashing users/groups universally with --numeric-ids:

# bup restore -C dest --numeric-ids --map-uid 1000=1042 /x/latest/y
Restoring: 97, done.

See Also

bup-save(1), bup-ftp(1), bup-fuse(1), bup-web(1)

Bup

Part of the bup(1) suite.

Authors

Avery Pennarun <apenwarr@gmail.com>.

Referenced By

bup(1), bup-ftp(1), bup-fuse(1), bup-meta(1), bup-save(1), bup-web(1).

2015-04-26 Bup unknown-d612d9a