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View Full Version : Using Knoppix for scsi tape-based disaster recovery



huffcr
10-18-2006, 10:12 PM
I generally work on computers with the premise "Worry now when I'm not in a hurry so when I REALLY have a problem, I know what to do and I know I've done it before", so...

I have FC5 up and running and can make dumps of disk partitions. The dumps look good when reviewed interactively with restore.

Problem is... how to read the dumps when the system is up in smoke, whether literally or figuratively.

Tried using FC5 install CD in rescue mode but won't find SCSI devices, so no /dev/nst0 device definition.

Knoppix DVD gets me further, but no cigar. It recognizes the tape and I can manipulate it with mt, but restore just comes back and says there's nothing on the tape.

Is this because I made the dumps with hardware compression on and I haven't been able to figure out how to set the /dev/nst0 device to use hardware compression?

It seems that the devices are read-only, so I can't use commands like:
# mt -f /dev/nst0 compression 1
or
# mt -f /dev/nst0 defcompression 1

The mt command is working okay since "# mt -f /dev/nst0 rewoff" kicks the tape back out like it should.

I can't help but wonder if there's some difference between dump/restore on Knoppix and FC5, but somehow that seems abhorrent.

Any suggestions?

huffcr
10-19-2006, 11:16 AM
I obviously stayed up too late.

I couldn't change defaults like:
#mt -f /dev/nst0 defcompression 1
but I could do:
#mt -f /dev/nst0 compression 1

The solution to my problem was to do:
#mt -f /dev/nst0 compression 1
#mt -f /dev/nst0 setblk 0

Then restore operations succeeded.

Mystery solved.