AMRESTORE(8)AMRESTORE(8)NAMEamrestore - extract backup images from an Amanda tape
SYNOPSISamrestore [ -r | -c | -C ] [ -p ] [ -h ] tapedevice |
holdingfile [ hostname [ diskname [ datestamp [ hostname [
diskname [ datestamp ... ]]]]]]
DESCRIPTION
Amrestore extracts backup images from the tape mounted on
tapedevice or from the holding file holdingfile that match
hostname, diskname and datestamp patterns given on the
command line. The tape or holding file must be in a for
mat written by the amdump or amflush program.
If diskname is not specified, all backups on the tape for
the previous hostname are candidates. If datestamp is not
specified, all backups on the tape for the previous host_
name and diskname are candidates. If no hostname,
diskname or datestamp are specified, every backup on the
tape is a candidate.
Hostname, diskname and datestamp are regular expressions
that may match more than one backup. For example, if
diskname is "rz[23]a", it would match disks rz2a and rz3a.
Hostname, diskname or datestamp may be an empty string
("") to match every host, disk or date (this is just an
abbreviation for ".*").
Datestamp is useful if amflush writes multiple backup runs
to a single tape.
Unless -p is used, candidate backup images are extracted
to files in the current directory named:
hostname.diskname.datestamp.dumplevel
OPTIONS-p Pipe output. The first matching backup image is
sent to standard output, which is normally a pipe
to restore or tar, then amrestore quits. It may be
run again to continue selecting backups to process.
Make sure you specify the no-rewind tapedevice when
doing this.
Note: restore may report "short read" errors when
reading from a pipe. Most versions of restore sup
port a blocking factor option to let you set the
read block size, and you should set it to 2. See
the example below.
-c Compress output using the fastest method the com
pression program provides. Amrestore normally
writes output files in a format understood by
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AMRESTORE(8)AMRESTORE(8)
restore or tar, even if the backups on the tape are
compressed. With the -c or -C option, amrestore
writes all files in compressed format, even if the
backups on the tape are not compressed. Output
file names will have a .Z or .gz extension depend
ing on whether compress or gzip is the preferred
compression program. This option is useful when
the current directory disk is small.
-C Compress output using the best method the compres
sion program provides (may be very CPU intensive).
See the notes above about the -c option.
-r Raw output. Backup images are output exactly as
they are on the tape, including the amdump headers.
Output file names will have a .RAW extension. This
option is only useful for debugging and other
strange circumstances.
-h Header output. The tape header block is output at
the beginning of each file. This is like -r except
-c or -C may also be used to compress the result.
Amrecover uses the header to determine the restore
program to use.
EXAMPLES
The following does an interactive restore of disk rz3g
from host seine, to restore particular files. Note the
use of the b option to restore, which causes it to read in
units of two 512-byte blocks (1 Kbyte) at a time. This
helps keep it from complaining about short reads.
% amrestore-p /dev/nrmt9 seine rz3g | restore -ivbf 2 -
The next example extracts all backup images for host
seine. This is the usual way to extract all data for a
host after a disk crash.
% amrestore /dev/nrmt9 seine
If the backup datestamp in the above example is 19910125
and seine has level 0 backups of disks rz1a and rz1g on
the tape, these files will be created in the current
directory:
seine.rz1a.19910125.0
seine.rz1g.19910125.0
You may also use amrestore to extract a backup image from
a holding disk file that has not yet been flushed to tape:
% amrestore-p /amanda/20001119/seine.rz1a.2 | restore -ivbf 2 -
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AMRESTORE(8)AMRESTORE(8)AUTHOR
James da Silva <jds@cs.umd.edu>
University of Maryland, College Park
SEE ALSOamanda(8), amdump(8), amflush(8), tar(1)restore(8)
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