
                             amrestore
Prev  Chapter 36. The Amanda Manual Pages.  Next

-------------------------------------------------------------------------------

Name

amrestore  extract backup images from an Amanda tape

Synopsis

amrestore [ -r | -c | -C ] [ -b | blocksize ] [ -f | fileno ] [ -l | label ] [-
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 disk file holdingfile that match hostname, diskname and datestamp
patterns given on the command line. The tape or holding file must be in a
format 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 hostname and diskname are candidates. If no hostname, diskname or
datestamp are specified, every backup on the tape is a candidate.
Hostname and diskname are special expressions described in the "HOST & DISK
EXPRESSION" section of amanda(8). Datestamp are special expression described in
the "DATESTAMP EXPRESSION" section of amanda(8). For example, if diskname is
"rz[23]a", it would match disks rz2a and rz3a.
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
Amrestore doesn't use a changer, it restore from the tape already loaded in the
tapedevice.

OPTIONS



  -b
      Set the blocksize used to read the tape or holding file. All holding
      files must be read with a blocksize of 32 KBytes. Amrestore should
      normally be able to determine the blocksize for tapes on its own and not
      need this parameter.

The default is 32 KBytes.


  -f
      Do a rewind followed by a fsf <fileno> before trying to restore an image.

  -l
      Check if we restoring from the tape with the right label

  -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 support 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 compression program
      provides. Amrestore normally writes output files in a format understood
      by 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 depending 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 compression 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.

If a header is written (-r or -h), only 32 KBytes are output regardless of the
tape blocksize. This makes the resulting image usable as a holding file.


  -o configoption
      See the "CONFIGURATION OVERWRITE" section in amanda(8).


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 -
Amrestore may be used to generate a listing of images on a tape:

% mt -f /dev/nrmt9 rewind
% amrestore -p /dev/nrmt9 no-such-host > /dev/null
This asks amrestore to find images for host no-such-host. It will not find any
entries that match, but along the way will report each image it skips.

CAVEATS

GNU-tar must be used to restore files from backup images created with the
GNUTAR dumptype. Vendor tar programs sometimes fail to read GNU tar images.

AUTHOR

James da Silva, <jds@amanda.org>, University of Maryland, College Park:
Original text
Stefan G. Weichinger, <sgw@amanda.org>, maintainer of the Amanda-documentation:
XML-conversion

SEE ALSO

amanda(8), amdump(8), amflush(8), tar(1) restore(8)
-------------------------------------------------------------------------------

Prev       Up       Next
amreport  Home  amrmtape

