XRESTORE(ADM) UNIX System V
Name
xrestore, xrestor - invokes XENIX incremental filesystem
restorer
Syntax
xrestore key [ arguments ]
xrestor key [ arguments ]
Description
xrestore 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. restor is an alternate spelling for the same
command.
c,C 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.
f Uses the first argument as the name of the archive
(backup device /dev/*) instead of the default.
F F is the number of the first file on the tape to read.
All files up to that point are skipped.
k Follow this option with the size of the backup volume.
This allows for reading multivolume dumps from media
such as floppies.
r,R The archive is read and loaded into the file system
specified in argument. This should not be done lightly
(see below). If the key is R, xrestore asks which
archive of a multivolume set to start on. This allows
xrestore to be interrupted and then restarted (an fsck
must be done before the restart).
t Prints the date the archive was written and the date
the file system was backed up.
T Prints a full listing of a dump tape. Similar to t.
x 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 multivolume 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.
X
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 a xrestore is used to
change the size of a file system.
Files
rst* Temporary files
/etc/default/restor Name of default archive device
The default archive unit varies with installation.
Notes
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.
Diagnostics
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.
See Also
xbackup(ADM), xdumpdir(ADM), fsck(ADM), mkfs(ADM), sddate(C)
Value Added
xrestor and xrestore are extensions of AT&T System V
developed by the Santa Cruz Operation.
(printed 2/15/90) XRESTORE(ADM)