MAN page from PLD amanda-client-2.4.4p3-3.i586.rpm

AMRESTORE

Section: Maintenance Commands (8)
Index 

NAME

amrestore - extract backup images from an Amanda tape 

SYNOPSIS

amrestore[-r|-c|-C][-bblocksize][-ffileno][-llabel][-p][-h]tapedevice|holdingfile[hostname[diskname[datestamp[hostname[diskname[datestamp...]]]]]] 

DESCRIPTION

Amrestoreextracts backup images from the tape mounted ontapedeviceor from the holding disk fileholdingfilethat matchhostname,disknameanddatestamppatterns given on the command line.The tape or holding file must be in a format written by theamdumporamflushprogram.

Ifdisknameis not specified, all backups on the tape for the previoushostnameare candidates.Ifdatestampis not specified, all backups on the tape for the previoushostnameanddisknameare candidates.If nohostname,disknameordatestampare specified, every backup on the tape is a candidate.

Hostnameanddisknameare special expression descibe in the "HOST & DISK EXPRESSION" sectionofamanda(8).Datestampare special expression describe in the "DATESTAMP EXPRESSION" sectionofamanda(8).For example, ifdisknameis "rz[23]a", it would match disksrz2aandrz3a.

Datestampis useful ifamflushwrites multiple backup runs to a single tape.

Unless-pis used,candidate backup images are extracted to filesin the current directory named:

hostname.diskname.datestamp.dumplevel

Amrestore doesn't use a changer, it restore from the tape already loadedin thetapedevice. 

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.Amrestoreshould normally be able to determine the blocksize for tapeson 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 rightlabel

-p

Pipe output.The first matching backup image is sent to standard output,which is normally a pipe torestoreortar,thenamrestorequits.It may be run again to continue selecting backups to process.Make sure you specify the no-rewindtapedevicewhen doing this.

Note:restoremay report "short read" errors when reading from a pipe.Most versions ofrestoresupport 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.Amrestorenormally writes output files in a format understood byrestoreortar,even if the backups on the tape are compressed.With the-cor-Coption,amrestorewrites all files in compressed format,even if the backups on the tape are not compressed.Output file names will have a.Zor.gzextension depending on whethercompressorgzipis 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-coption.

-r

Raw output.Backup images are output exactly as they are on the tape,including theamdumpheaders.Output file names will have a.RAWextension.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-rexcept-cor-Cmay also be used to compress the result.Amrecoveruses 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. 

EXAMPLES

The following does an interactive restore of diskrz3gfrom hostseine,to restore particular files.Note the use of theboption torestore,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 hostseine.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 is19910125andseinehas level 0 backups of disksrz1aandrz1gon the tape,these files will be created in the current directory:

seine.rz1a.19910125.0seine.rz1g.19910125.0

You may also useamrestoreto extract a backup image from a holding diskfile that has not yet been flushed to tape:

% amrestore -p /amanda/20001119/seine.rz1a.2 | restore -ivbf 2 -

Amrestoremay 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 asksamrestoreto find images for hostno-such-host.It will not find any entries that match, but along the way will reporteach image it skips. 

CAVEATS

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

AUTHOR

James da Silva <jdsAATTcs.umd.edu>
University of Maryland, College Park 

SEE ALSO

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

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Index

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

EXAMPLES

CAVEATS

AUTHOR

SEE ALSO

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