'\" t .\" Title: amrestore .\" Author: James da Silva .\" Generator: DocBook XSL Stylesheets vsnapshot_8273 .\" Date: 11/05/2009 .\" Manual: System Administration Commands .\" Source: Amanda 2.6.1p2 .\" Language: English .\" .TH "AMRESTORE" "8" "11/05/2009" "Amanda 2\&.6\&.1p2" "System Administration Commands" .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" amrestore \- extract backup images from an \fIAmanda\fR tape .SH "SYNOPSIS" .HP \w'\fBamrestore\fR\ 'u \fBamrestore\fR [\-r | \-c | \-C] [\-b | \fIblocksize\fR] [\-f | \fIfileno\fR] [\-l | \fIlabel\fR] [\-p] [\-h] \fItapedevice\fR|\ \fIholdingfile\fR [\fIhostname\fR [\fIdiskname\fR [\fIdatestamp\fR [\fIhostname\fR [\fIdiskname\fR [\fIdatestamp\fR | \&.\&.\&.]]]]]] .SH "DESCRIPTION" .PP \fBAmrestore\fR extracts backup images from the tape mounted on \fItapedevice\fR or from the holding disk file \fIholdingfile\fR that match \fIhostname\fR, \fIdiskname\fR and \fIdatestamp\fR patterns given on the command line\&. The tape or holding file must be in a format written by the \fBamdump\fR or \fBamflush\fR program\&. .PP If \fIdiskname\fR is not specified, all backups on the tape for the previous \fIhostname\fR are candidates\&. If \fIdatestamp\fR is not specified, all backups on the tape for the previous \fIhostname\fR and \fIdiskname\fR are candidates\&. If no \fIhostname\fR, \fIdiskname\fR or \fIdatestamp\fR are specified, every backup on the tape is a candidate\&. .PP \fIHostname\fR and \fIdiskname\fR are special expressions described in the "HOST & DISK EXPRESSION" section of \fBamanda\fR(8)\&. \fIDatestamp\fR are special expression described in the "DATESTAMP EXPRESSION" section of \fBamanda\fR(8)\&. For example, if \fIdiskname\fR is "rz[23]a", it would match disks \fBrz2a\fR and \fBrz3a\fR\&. .PP \fIDatestamp\fR is useful if \fBamflush\fR writes multiple backup runs to a single tape\&. .PP Unless \fB\-p\fR is used, candidate backup images are extracted to files in the current directory named: .PP \fIhostname\&.diskname\&.datestamp\&.dumplevel\fR .PP Amrestore doesn\'t use a changer, it restore from the tape already loaded in the \fItapedevice\&.\fR .SH "OPTIONS" .PP \fB\-b\fR .RS 4 Set the blocksize used to read the tape or holding file\&. All holding files must be read with a blocksize of 32 KBytes\&. \fBAmrestore\fR should normally be able to determine the blocksize for tapes on its own and not need this parameter\&. .RE .PP The default is 32 KBytes\&. .PP \fB\-f\fR .RS 4 Do a rewind followed by a fsf before trying to restore an image\&. .RE .PP \fB\-l\fR .RS 4 Check if we restoring from the tape with the right \fIlabel\fR .RE .PP \fB\-p\fR .RS 4 Pipe output\&. The first matching backup image is sent to standard output, which is normally a pipe to \fBrestore\fR or \fBtar\fR, then \fBamrestore\fR quits\&. It may be run again to continue selecting backups to process\&. Make sure you specify the no\-rewind \fItapedevice\fR when doing this\&. .RE .PP Note: \fBrestore\fR may report "short read" errors when reading from a pipe\&. Most versions of \fBrestore\fR support a blocking factor option to let you set the read block size, and you should set it to 2\&. See the example below\&. .PP \fB\-c\fR .RS 4 Compress output using the fastest method the compression program provides\&. \fBAmrestore\fR normally writes output files in a format understood by \fBrestore\fR or \fBtar\fR, even if the backups on the tape are compressed\&. With the \fB\-c\fR or \fB\-C\fR option, \fBamrestore\fR writes all files in compressed format, even if the backups on the tape are not compressed\&. Output file names will have a \fB\&.Z\fR or \fB\&.gz\fR extension depending on whether \fBcompress\fR or \fBgzip\fR is the preferred compression program\&. This option is useful when the current directory disk is small\&. .RE .PP \fB\-C\fR .RS 4 Compress output using the best method the compression program provides (may be very CPU intensive)\&. See the notes above about the \fB\-c\fR option\&. .RE .PP \fB\-r\fR .RS 4 Raw output\&. Backup images are output exactly as they are on the tape, including the \fBamdump\fR headers\&. Output file names will have a \fB\&.RAW\fR extension\&. This option is only useful for debugging and other strange circumstances\&. .RE .PP \fB\-h\fR .RS 4 Header output\&. The tape header block is output at the beginning of each file\&. This is like \fB\-r\fR except \fB\-c\fR or \fB\-C\fR may also be used to compress the result\&. \fBAmrecover\fR uses the header to determine the restore program to use\&. .RE .PP 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\&. .PP \fB\-o\fR \fIconfigoption\fR .RS 4 See the "\fBCONFIGURATION OVERRIDE\fR" section in \fBamanda\fR(8)\&. .RE .SH "EXAMPLES" .PP The following does an interactive restore of disk \fIrz3g\fR from host \fIseine\fR, to restore particular files\&. Note the use of the \fBb\fR option to \fBrestore\fR, 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\&. .sp .if n \{\ .RS 4 .\} .nf % amrestore \-p /dev/nrmt9 seine rz3g | restore \-ivbf 2 \- .fi .if n \{\ .RE .\} .PP The next example extracts all backup images for host \fIseine\fR\&. This is the usual way to extract all data for a host after a disk crash\&. .sp .if n \{\ .RS 4 .\} .nf % amrestore /dev/nrmt9 seine .fi .if n \{\ .RE .\} .PP If the backup datestamp in the above example is 19910125 and \fIseine\fR has level 0 backups of disks \fIrz1a\fR and \fIrz1g\fR on the tape, these files will be created in the current directory: .sp .if n \{\ .RS 4 .\} .nf seine\&.rz1a\&.19910125\&.0 seine\&.rz1g\&.19910125\&.0 .fi .if n \{\ .RE .\} .PP You may also use \fBamrestore\fR to extract a backup image from a holding disk file that has not yet been flushed to tape: .sp .if n \{\ .RS 4 .\} .nf % amrestore \-p /amanda/20001119/seine\&.rz1a\&.2 | restore \-ivbf 2 \- .fi .if n \{\ .RE .\} .PP \fBAmrestore\fR may be used to generate a listing of images on a tape: .sp .if n \{\ .RS 4 .\} .nf % mt \-f /dev/nrmt9 rewind % amrestore \-p /dev/nrmt9 no\-such\-host > /dev/null .fi .if n \{\ .RE .\} .PP This asks \fBamrestore\fR to find images for host \fBno\-such\-host\fR\&. It will not find any entries that match, but along the way will report each image it skips\&. .SH "CAVEATS" .PP \fBGNU\-tar\fR must be used to restore files from backup images created with the GNUTAR dumptype\&. Vendor tar programs sometimes fail to read GNU tar images\&. .SH "SEE ALSO" .PP \fBamanda\fR(8), \fBamdump\fR(8), \fBamflush\fR(8), \fBtar\fR(1), \fBrestore\fR(8), : http://wiki.zmanda.com .SH "AUTHORS" .PP \fBJames da Silva\fR <\&jds@amanda\&.org\&> .PP \fBStefan G\&. Weichinger\fR <\&sgw@amanda\&.org\&>