xfsrestore

xfsrestore(8)               System Manager's Manual              xfsrestore(8)



NAME
       xfsrestore - XFS filesystem incremental restore utility

SYNOPSIS
       xfsrestore -h
       xfsrestore [ options ] -f source [ -f source ... ] dest
       xfsrestore [ options ] - dest
       xfsrestore -I [ subopt=value ... ]

DESCRIPTION
       xfsrestore restores filesystems from dumps produced by xfsdump(8).  Two
       modes of operation are available: simple and cumulative.

       The default is simple mode.  xfsrestore populates the specified
       destination directory, dest, with the files contained in the dump
       media.

       The -r option specifies the cumulative mode.  Successive invocations of
       xfsrestore are used to apply a chronologically ordered sequence of
       delta dumps to a base (level 0) dump.  The contents of the filesystem
       at the time each dump was produced is reproduced.  This can involve
       adding, deleting, renaming, linking, and unlinking files and
       directories.

       A delta dump is defined as either an incremental dump (xfsdump -l
       option with level > 0) or a resumed dump (xfsdump -R option).  The
       deltas must be applied in the order they were produced.  Each delta
       applied must have been produced with the previously applied delta as
       its base.

       xfsrestore keeps state information in the xfsrestorehousekeepingdir, to
       inform subsequent invocations when used in cumulative mode, or in the
       event a restore is interrupted.  To ensure that the state information
       can be processed, a compatible version of xfsrestore must be used for
       each subsequent invocation. Additionally, each invocation must run on a
       system of the same endianness and page size.

       The options to xfsrestore are:

       -a housekeeping
            Each invocation of xfsrestore creates a directory called
            xfsrestorehousekeepingdir.  This directory is normally created
            directly under the dest directory.  The -a option allows the
            operator to specify an alternate directory, housekeeping, in which
            xfsrestore creates the xfsrestorehousekeepingdir directory.  When
            performing a cumulative (-r option) restore or resuming (-R
            option) a restore, each successive invocation must specify the
            same alternate directory.

       -b blocksize
            Specifies the blocksize, in bytes, to be used for the restore.
            For other drives such as DAT or 8 mm , the same blocksize used for
            the xfsdump operation must be specified to restore the tape.  The
            default block size is 1Mb.

       -c progname
            Use the specified program to alert the operator when a media
            change is required. The alert program is typically a script to
            send a mail or flash a window to draw the operator's attention.

       -e   Prevents xfsrestore from overwriting existing files in the dest
            directory.

       -f source [ -f source ... ]
            Specifies a source of the dump to be restored.  This can be the
            pathname of a device (such as a tape drive), a regular file or a
            remote tape drive (see rmt(8)).  This option must be omitted if
            the standard input option (a lone - preceding the dest
            specification) is specified.

       -i   Selects interactive operation.  Once the on-media directory
            hierarchy has been read, an interactive dialogue is begun.  The
            operator uses a small set of commands to peruse the directory
            hierarchy, selecting files and subtrees for extraction.  The
            available commands are given below.  Initially nothing is
            selected, except for those subtrees specified with -s command line
            options.

            ls [arg]       List the entries in the current directory or the
                           specified directory, or the specified non-directory
                           file entry.  Both the entry's original inode number
                           and name are displayed.  Entries that are
                           directories are appended with a `/'.  Entries that
                           have been selected for extraction are prepended
                           with a `*'.

            cd [arg]       Change the current working directory to the
                           specified argument, or to the filesystem root
                           directory if no argument is specified.

            pwd            Print the pathname of the current directory,
                           relative to the filesystem root.

            add [arg]      The current directory or specified file or
                           directory within the current directory is selected
                           for extraction.  If a directory is specified, then
                           it and all its descendents are selected.  Entries
                           that are selected for extraction are prepended with
                           a `*' when they are listed by ls.

            delete [arg]   The current directory or specified file or
                           directory within the current directory is
                           deselected for extraction.  If a directory is
                           specified, then it and all its descendents are
                           deselected.  The most expedient way to extract most
                           of the files from a directory is to select the
                           directory and then deselect those files that are
                           not needed.

            extract        Ends the interactive dialogue, and causes all
                           selected subtrees to be restored.

            quit           xfsrestore ends the interactive dialogue and
                           immediately exits, even if there are files or
                           subtrees selected for extraction.

            help           List a summary of the available commands.

       -m   Use the minimal tape protocol.  This option cannot be used without
            specifying a blocksize to be used (see -b option above).

       -n file
            Allows xfsrestore to restore only files newer than file.  The
            modification time of file (i.e., as displayed with the ls -l
            command) is compared to the inode modification time of each file
            on the source media (i.e., as displayed with the ls -lc command).
            A file is restored from media only if its inode modification time
            is greater than or equal to the modification time of file.

       -o   Restore file and directory owner/group even if not root.  When run
            with an effective user id of root, xfsrestore restores owner and
            group of each file and directory.  When run with any other
            effective user id it does not, unless this option is specified.

       -p interval
            Causes progress reports to be printed at intervals of interval
            seconds.  The interval value is approximate, xfsrestore will delay
            progress reports to avoid undue processing overhead.

       -q   Source tape drive is a QIC tape.  QIC tapes only use a 512 byte
            blocksize, for which xfsrestore must make special allowances.

       -r   Selects the cumulative mode of operation. The -a and destination
            options must be the same for each invocation.

       -s subtree
            Specifies a subtree to restore.  Any number of -s options are
            allowed.  The restore is constrained to the union of all subtrees
            specified.  Each subtree is specified as a pathname relative to
            the restore dest.  If a directory is specified, the directory and
            all files beneath that directory are restored.

       -t   Displays the contents of the dump, but does not create or modify
            any files or directories.  It may be desirable to set the
            verbosity level to silent when using this option.

       -v verbosity
       -v subsys=verbosity[,subsys=verbosity,...]
            Specifies the level of detail used for messages displayed during
            the course of the restore. The verbosity argument can be passed as
            either a string or an integer. If passed as a string the following
            values may be used: silent, verbose, trace, debug, or nitty.  If
            passed as an integer, values from 0-5 may be used. The values 0-4
            correspond to the strings already listed. The value 5 can be used
            to produce even more verbose debug output.

            The first form of this option activates message logging across all
            restore subsystems. The second form allows the message logging
            level to be controlled on a per-subsystem basis. The two forms can
            be combined (see the example below). The argument subsys can take
            one of the following values: general, proc, drive, media,
            inventory, and tree.

            For example, to restore the root filesystem with tracing activated
            for all subsystems:

                 # xfsrestore -v trace -f /dev/tape /

            To enable debug-level tracing for drive and media operations:

                 # xfsrestore -v drive=debug,media=debug -f /dev/tape /

            To enable tracing for all subsystems, and debug level tracing for
            drive operations only:

                 # xfsrestore -v trace,drive=debug -f /dev/tape /


       -A   Do not restore extended file attributes.  When restoring a
            filesystem managed within a DMF environment this option should not
            be used. DMF stores file migration status within extended
            attributes associated with each file. If these attributes are not
            preserved when the filesystem is restored, files that had been in
            migrated state will not be recallable by DMF. Note that dumping of
            extended file attributes is also optional.

       -B   Change the ownership and permissions of the destination directory
            to match those of the root directory of the dump.

       -D   Restore DMAPI (Data Management Application Programming Interface)
            event settings. If the restored filesystem will be managed within
            the same DMF environment as the original dump it is essential that
            the -D option be used. Otherwise it is not usually desirable to
            restore these settings.

       -E   Prevents xfsrestore from overwriting newer versions of files.  The
            inode modification time of the on-media file is compared to the
            inode modification time of corresponding file in the dest
            directory.  The file is restored only if the on-media version is
            newer than the version in the dest directory.  The inode
            modification time of a file can be displayed with the ls -lc
            command.

       -F   Inhibit interactive operator prompts.  This option inhibits
            xfsrestore from prompting the operator for verification of the
            selected dump as the restore target and from prompting for any
            media change.

       -I   Causes the xfsdump inventory to be displayed (no restore is
            performed).  Each time xfsdump is used, an online inventory in
            /var/lib/xfsdump/inventory is updated.  This is used to determine
            the base for incremental dumps.  It is also useful for manually
            identifying a dump session to be restored (see the -L and -S
            options).  Suboptions to filter the inventory display are
            described later.

       -J   Inhibits inventory update when on-media session inventory
            encountered during restore.  xfsrestore opportunistically updates
            the online inventory when it encounters an on-media session
            inventory, but only if run with an effective user id of root and
            only if this option is not given.

       -K   Force xfsrestore to use dump format 2 generation numbers. Normally
            the need for this is determined automatically, but this option is
            required on the first xfsrestore invocation in the rare case that
            a cumulative restore begins with a format 3 (or newer) dump and
            will be followed by a format 2 dump.

       -L session_label
            Specifies the label of the dump session to be restored.  The
            source media is searched for this label.  It is any arbitrary
            string up to 255 characters long.  The label of the desired dump
            session can be copied from the inventory display produced by the
            -I option.

       -O options_file
            Insert the options contained in options_file into the beginning of
            the command line.  The options are specified just as they would
            appear if typed into the command line.  In addition, newline
            characters (\n) can be used as whitespace.  The options are placed
            before all options actually given on the command line, just after
            the command name.  Only one -O option can be used.  Recursive use
            is ignored.  The destination directory cannot be specified in
            options_file.

       -Q   Force completion of an interrupted restore session.  This option
            is required to work around one specific pathological scenario.
            When restoring a dump session which was interrupted due to an EOM
            condition and no online session inventory is available, xfsrestore
            cannot know when the restore of that dump session is complete.
            The operator is forced to interrupt the restore session.  In that
            case, if the operator tries to subsequently apply a resumed dump
            (using the -r option), xfsrestore refuses to do so.  The operator
            must tell xfsrestore to consider the base restore complete by
            using this option when applying the resumed dump.

       -R   Resume a previously interrupted restore.  xfsrestore can be
            interrupted at any time by pressing the terminal interrupt
            character (see stty(1)).  Use this option to resume the restore.
            The -a and destination options must be the same.

       -S session_id
            Specifies the session UUID of the dump session to be restored.
            The source media is searched for this UUID.  The UUID of the
            desired dump session can be copied from the inventory display
            produced by the -I option.

       -T   Inhibits interactive dialogue timeouts.  xfsrestore prompts the
            operator for media changes.  This dialogue normally times out if
            no response is supplied.  This option prevents the timeout.

       -X subtree
            Specifies a subtree to exclude.  This is the converse of the -s
            option.  Any number of -X options are allowed.  Each subtree is
            specified as a pathname relative to the restore dest.  If a
            directory is specified, the directory and all files beneath that
            directory are excluded.

       -Y io_ring_length
            Specify I/O buffer ring length.  xfsrestore uses a ring of input
            buffers to achieve maximum throughput when restoring from tape
            drives.  The default ring length is 3.  However, this is not
            currently enabled on Linux yet, making this option benign.

       -    A lone - causes the standard input to be read as the source of the
            dump to be restored.  Standard input can be a pipe from another
            utility (such as xfsdump(8)) or a redirected file.  This option
            cannot be used with the -f option.  The - must follow all other
            options, and precede the dest specification.

       The dumped filesystem is restored into the dest directory.  There is no
       default; the dest must be specified.

NOTES
   Cumulative Restoration
       A base (level 0) dump and an ordered set of delta dumps can be
       sequentially restored, each on top of the previous, to reproduce the
       contents of the original filesystem at the time the last delta was
       produced.  The operator invokes xfsrestore once for each dump.  The -r
       option must be specified.  The dest directory must be the same for all
       invocations.  Each invocation leaves a directory named
       xfsrestorehousekeeping in the dest directory (however, see the -a
       option above).  This directory contains the state information that must
       be communicated between invocations.  The operator must remove this
       directory after the last delta has been applied.

       xfsrestore also generates a directory named orphanage in the dest
       directory.  xfsrestore removes this directory after completing a simple
       restore.  However, if orphanage is not empty, it is not removed.  This
       can happen if files present on the dump media are not referenced by any
       of the restored directories.  The orphanage has an entry for each such
       file.  The entry name is the file's original inode number, a ".", and
       the file's generation count modulo 4096 (only the lower 12 bits of the
       generation count are used).

       xfsrestore does not remove the orphanage after cumulative restores.
       Like the xfsrestorehousekeeping directory, the operator must remove it
       after applying all delta dumps.

   Media Management
       A dump consists of one or more media files contained on one or more
       media objects.  A media file contains all or a portion of the
       filesystem dump.  Large filesystems are broken up into multiple media
       files to minimize the impact of media dropouts, and to accommodate
       media object boundaries (end-of-media).

       A media object is any storage medium: a tape cartridge, a remote tape
       device (see rmt(8)), a regular file, or the standard input (currently
       other removable media drives are not supported).  Tape cartridges can
       contain multiple media files, which are typically separated by (in tape
       parlance) file marks.  If a dump spans multiple media objects, the
       restore must begin with the media object containing the first media
       file dumped.  The operator is prompted when the next media object is
       needed.

       Media objects can contain more than one dump.  The operator can select
       the desired dump by specifying the dump label (-L option), or by
       specifying the dump UUID (-S option).  If neither is specified,
       xfsrestore scans the entire media object, prompting the operator as
       each dump session is encountered.

       The inventory display (-I option) is useful for identifying the media
       objects required.  It is also useful for identifying a dump session.
       The session UUID can be copied from the inventory display to the -S
       option argument to unambiguously identify a dump session to be
       restored.

       Dumps placed in regular files or the standard output do not span
       multiple media objects, nor do they contain multiple dumps.

   Inventory
       Each dump session updates an inventory database in
       /var/lib/xfsdump/inventory.  This database can be displayed by invoking
       xfsrestore with the -I option.  The display uses tabbed indentation to
       present the inventory hierarchically.  The first level is filesystem.
       The second level is session.  The third level is media stream
       (currently only one stream is supported).  The fourth level lists the
       media files sequentially composing the stream.

       The following suboptions are available to filter the display.

       -I depth=n
            (where n is 1, 2, or 3) limits the hierarchical depth of the
            display. When n is 1, only the filesystem information from the
            inventory is displayed. When n is 2, only filesystem and session
            information are displayed. When n is 3, only filesystem, session
            and stream information are displayed.

       -I level=n
            (where n is the dump level) limits the display to dumps of that
            particular dump level.

       The display may be restricted to media files contained in a specific
       media object.

       -I mobjid=value
            (where value is a media ID) specifies the media object by its
            media ID.

       -I mobjlabel=value
            (where value is a media label) specifies the media object by its
            media label.

       Similarly, the display can be restricted to a specific filesystem.

       -I mnt=mount_point
            (that is, [hostname:]pathname), identifies the filesystem by
            mountpoint.  Specifying the hostname is optional, but may be
            useful in a clustered environment where more than one host can be
            responsible for dumping a filesystem.

       -I fsid=filesystem_id
            identifies the filesystem by filesystem ID.

       -I dev=device_pathname
            (that is, [hostname:]device_pathname) identifies the filesystem by
            device.  As with the mnt filter, specifying the hostname is
            optional.

       More than one of these suboptions, separated by commas, may be
       specified at the same time to limit the display of the inventory to
       those dumps of interest.  However, at most four suboptions can be
       specified at once: one to constrain the display hierarchy depth, one to
       constrain the dump level, one to constrain the media object, and one to
       constrain the filesystem.

       For example, -I depth=1,mobjlabel="tape 1",mnt=host1:/test_mnt would
       display only the filesystem information (depth=1) for those filesystems
       that were mounted on host1:/test_mnt at the time of the dump, and only
       those filesystems dumped to the media object labeled "tape 1".

       Dump records may be removed (pruned) from the inventory using the
       xfsinvutil program.

       An additional media file is placed at the end of each dump stream.
       This media file contains the inventory information for the current dump
       session.  If the online inventory files in /var/lib/xfsdump/inventory
       are missing information for the current dump session, then the
       inventory information in the media file is automatically added to the
       files in /var/lib/xfsdump/inventory.  If you wish to incorporate the
       inventory information from the media file without restoring any data,
       you may do so using the -t option:

            # xfsrestore -t -f /dev/tape

       This is useful to rebuild the inventory database if it is ever lost or
       corrupted.  The only caveat is that xfsrestore needs to read through
       the entire dump in order to reach the inventory media file.  This could
       become time consuming for dump sessions with large media files.

   Media Errors
       xfsdump is tolerant of media errors, but cannot do error correction.
       If a media error occurs in the body of a media file, the filesystem
       file represented at that point is lost.  The bad portion of the media
       is skipped, and the restoration resumes at the next filesystem file
       after the bad portion of the media.

       If a media error occurs in the beginning of the media file, the entire
       media file is lost.  For this reason, large dumps are broken into a
       number of reasonably sized media files.  The restore resumes with the
       next media file.

   Quotas
       When xfsdump dumps a filesystem with user quotas, it creates a file in
       the root of the dump called xfsdump_quotas.  xfsrestore can restore
       this file like any other file included in the dump.  This file can be
       processed by the restore command of xfs_quota(8) to reactivate the
       quotas.  However, the xfsdump_quotas file contains information which
       may first require modification; specifically the filesystem name and
       the user ids.  If you are restoring the quotas for the same users on
       the same filesystem from which the dump was taken, then no modification
       will be necessary.  However, if you are restoring the dump to a
       different filesystem, you will need to:

       - ensure the new filesystem is mounted with the quota option

       - modify the xfsdump_quotas file to contain the new filesystem name

       - ensure the uids in the xfsdump_quotas file are correct

       Once the quota information has been verified, the restore command of
       xfs_quota (8) can be used to apply the quota limits to the filesystem.

       Group and project quotas are handled in a similar fashion and will be
       restored in files called xfsdump_quotas_group and xfsdump_quotas_proj,
       respectively.

EXAMPLES
       To restore the root filesystem from a locally mounted tape:

            # xfsrestore -f /dev/tape /

       To restore from a remote tape, specifying the dump session id:

            # xfsrestore -L session_1 -f otherhost:/dev/tape /new

       To restore the contents a of a dump to another subdirectory:

            # xfsrestore -f /dev/tape /newdir

       To copy the contents of a filesystem to another directory (see
       xfsdump(8)):

            # xfsdump -J - / | xfsrestore -J - /new


FILES
       /var/lib/xfsdump/inventory
                                dump inventory database

SEE ALSO
       rmt(8), xfsdump(8), xfsinvutil(8), xfs_quota(8), attr_set(2).

DIAGNOSTICS
       The exit code is 0 on normal completion, and non-zero if an error
       occurred or the restore was terminated by the operator.

       For all verbosity levels greater than 0 (silent) the final line of the
       output shows the exit status of the restore. It is of the form:

            xfsdump: Restore Status: code

       Where code takes one of the following values: SUCCESS (normal
       completion), INTERRUPT (interrupted), QUIT (media no longer usable),
       INCOMPLETE (restore incomplete), FAULT (software error), and ERROR
       (resource error).  Every attempt will be made to keep both the syntax
       and the semantics of this log message unchanged in future versions of
       xfsrestore.  However, it may be necessary to refine or expand the set
       of exit codes, or their interpretation at some point in the future.

BUGS
       Pathnames of restored non-directory files (relative to the dest
       directory) must be 1023 characters (MAXPATHLEN) or less.  Longer
       pathnames are discarded and a warning message displayed.

       There is no verify option to xfsrestore.  This would allow the operator
       to compare a filesystem dump to an existing filesystem, without
       actually doing a restore.

       The interactive commands (-i option) do not understand regular
       expressions.

       When the minimal rmt option is specified, xfsrestore applies it to all
       remote tape sources. The same blocksize (specified by the -b option) is
       used for all these remote drives.

       xfsrestore uses the alert program only when a media change is required.

       Cumulative mode (-r option) requires that the operator invoke
       xfsrestore for the base and for each delta to be applied in sequence to
       the base.  It would be better to allow the operator to identify the
       last delta in the sequence of interest, and let xfsrestore work
       backwards from that delta to identify and apply the preceding deltas
       and base dump, all in one invocation.



                                                                 xfsrestore(8)