xrestore, xrestor -- invoke XENIX incremental filesystem restorer


xrestore key [ arguments ]

xrestor key [ arguments ]


The xrestore command is used to read archive media backed up with the xbackup(ADM) command.

The key specifies what is to be done. key is one of the characters cC, rR, tT, or xX optionally combined with k and/or f or F. xrestor is an alternate spelling for the same command.

Verify (check) a dump tape. Used after a dump is made to make sure the tape has no I/O errors or bad checksums. C is the same as c except that it provides a higher level of checking.

Uses the first argument as the name of the archive (backup device /dev/*) instead of the default.

F is the number of the first file on the tape to read. All files up to that point are skipped.

Follow this option with the size of the backup volume. This allows for reading multi-volume dumps from media such as floppies.

The archive is read and loaded into the file system specified in argument. This should not be done without proper consideration (see below). If the key is R, xrestore asks which archive of a multi-volume set to start on. This allows xrestore to be interrupted and then restarted (an fsck must be done before the restart).

Prints the date the archive was written and the date the file system was backed up.

Prints a full listing of a dump tape. Similar to t.

Each file on the archive named by an argument is extracted. The filename has all ``mount'' prefixes removed; for example, if /usr is a mounted file system, /usr/bin/lpr is named /bin/lpr on the archive.

The extracted file is placed in a file with a numeric name supplied by xrestore (actually the inode number). In order to keep the amount of archive read to a minimum, the following procedure is recommended:

  1. Mount volume 1 of the set of backup archives.

  2. Type the xrestore command with the appropriate key and arguments.

  3. xrestore will check xdumpdir, then announce whether or not it found the files, give the numeric name that it will assign to the file, and in the case of a tape, rewind to the start of the archive.

  4. It then asks you to ``mount the desired tape volume.'' Type the number of the volume you choose. On a multi-volume backup, the recommended procedure is to mount the last through the first volumes, in that order. xrestore checks to see if any of the requested files are on the mounted archive (or a later archive, thus the reverse order). If the requested files are not there, xrestore doesn't read through the tape. If you are working with a single-volume backup or if the number of files being xrestored is large, respond to the query with ``1'' and xrestore will read the archives in sequential order.

Same as x except that files are replaced in original location. When you use this option, omit the initial slash (/) in the filename on the xrestore command line.

The r option should only be used to xrestore a complete backup archive onto a clear file system, or to xrestore an incremental backup archive onto a file system so created. It should not be used to xrestore a backup archive onto the root file system. Thus:

/etc/mkfs /dev/hd1 10000
xrestore r /dev/hd1

is a typical sequence to xrestore a complete backup. Another xrestore can be done to get an incremental backup in on top of this.

A xbackup followed by a mkfs and an xrestore is used to change the size of a file system.


There are various diagnostics involved with reading the archive and writing the disk. There are also diagnostics if the i-list or the free list of the file system is not large enough to hold the dump.

If the dump extends over more than one disk or tape, xrestore may ask you to change disks or tapes. Reply with a newline when the next unit has been mounted.


It is not possible to successfully xrestore an entire active root file system.

Note also that xrestore may be unable to xrestore more than one filesystem from the tape devices /dev/nrct0 and /dev/nrct2.


temporary files

name of default archive device
The default archive unit varies with installation.

See also

fsck(ADM), mkfs(ADM), sddate(C), xbackup(ADM), xdumpdir(ADM)

Standards conformance

xrestor and xrestore are not part of any currently supported standard; they are extensions of AT&T System V developed by The Santa Cruz Operation, Inc.
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003