Using AMANDA
This is an excerpt from the
book Unix Backup & Recovery. This
page is only part of the AMANDA chapter that is available here
for free.
Restoring Without AMANDA
The AMANDA tape format is deliberately
simple and restoring data can be done without any AMANDA tools if necessary.
The first tape file is a volume label with the tape VSN and date it was
written. It is not in ANSI VOL1 format, but is plain text. Each file after
that contains one image using 32 KByte blocks. The first block is an AMANDA
header with client, area and options used to create the image. As with
the volume label, the header is not in ANSI format, but is plain text.
The image follows, starting at the next tape block, until end of file.
To retrieve an image with
standard Unix utilities if amrestore is not available, position the tape
to the image, then use dd to read it:
# mt rewind
# mt fsf NN
# dd if=$TAPE bs=32k
skip=1 of=dump_image
The skip=1 option tells dd
to skip over the AMANDA file header. Without the of= option, dd writes
the image to standard output, which can be piped to the decompression program,
if needed, and then to the client restore program.
Since the image header is
text, it may be viewed with:
# mt rewind
# mt fsf NN
# dd if=$TAPE bs=32k
count=1
In addition to describing
the image, it contains text showing the commands needed to do a restore.
Here's a typical entry for the root filesystem on pete.cc.purdue.edu. It
is a level 1 dump done without compression using the vendor ufsdump program:
AMANDA: FILE 19981206
pete.cc.purdue.edu / lev 1
comp N program /usr/sbin/ufsdump
To restore, position the
tape at start of file and run:
# dd if=$TAPE bs=32k
skip=1 | /usr/sbin/ufsrestore -f... -
As with any backup system,
test these procedures while in normal production so the principles and
techniques are familiar when disaster strikes.
Copyright (c) 2000, O'Reilly
and Associates. All Rights Reserved.
|
