Only one backup per tape? Really?
W. Paul Zola
paulz at sco.COM
Mon Dec 24 14:52:12 AEST 1990
In article <NELSON.90Dec12212501 at image.clarkson.edu>
nelson at clutx.clarkson.edu (aka NELSON at CLUTX.BITNET) writes:
}I've got two filesystems to back up, and only one tape drive, and I'd
}like to do unattended backups. Can I really only back up one
}filesystem per tape? Well, of course I mean, will I be able to *restore*
}from a tape with two backups on it?
}
}--
}--russ (nelson at clutx [.bitnet | .clarkson.edu]) FAX 315-268-7600
}It's better to get mugged than to live a life of fear -- Freeman Dyson
}I joined the League for Programming Freedom, and I hope you'll join too.
You don't say if you are using an SCO system or not, but from the
newsgroup I assume you are. The following article from the SCO
Information Tools database should help with your problem.
################## cut here ################ cut here ##################
How to store multiple archives or backups onto a single cartridge tape
KEYWORDS: no rewind QIC cartridge tape drives multiple archives tar cpio
backup /dev/nrct0 xenix
RELEASE: SCO XENIX Release 2.2 and later
SCO UNIX System V/386 Generic
PROBLEM: How can more than one backup, cpio, or tar archive be written
to a single tape cartridge?
SOLUTION: The no-rewind device allows the SCO XENIX user to write and read
QIC tapes without automatically rewinding them, as is the default for
other tape devices. Using the no-rewind tape device /dev/nrct0,
multiple files or archives can be written to a tape. For example,
the following three commands, if given in succession, will write
three tar archives to the tape currently in the tape drive:
tar cvbf 20 /dev/nrct0 /a
tape -c wfm
tar cvbf 20 /dev/nrct0 /b
tape -c wfm
tar cvbf 20 /dev/nrct0 /c
Once the desired archives have been written, the tape must be rewound
before it may be read. Use the "tape rewind" command to rewind the
tape. After multiple items have been written, the "rfm" (read file
mark) option to the tape(C) command can be used to seek to the
desired item. To retrieve the third tar archive written by the
example commands above, use the following command:
tape -c rfm; tape -c rfm; tar xv6
The no-rewind device may be used in the same way to read and write
multiple cpio(C) archives, or backups from the backup(C) command.
NOTE: There is no no-rewind device available for Irwin tape drives, so the
above techniques apply to quarter-inch cartridge (QIC) tape drives only.
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I hope this helps with your problem, and is of general interest as well.
-
Paul Zola Software Support Engineer
paulz at sco.COM
We only know in theory what we are doing. - Kate Bush
DISCLAIMER: I speak for myself, and not for SCO.
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