Dump/restore mystery (off topic)

From: Triffid (triffid_at_nebula.net)
Date: 11/29/04 

Date: Sun, 28 Nov 2004 22:51:37 -0500

Not a Solaris question, actually CX/SX - but the relevant newsgroups
have been dormant for 10+ years so I'll try my luck here. I think I need
a lateral thought, but none have come to me yet...

I am responsible for some ancient Harris systems running CX/SX. Some
background here:

http://tinyurl.com/5e3s4

One of them refused to reboot after an unscheduled power outage last
weekend - hard disk failure. This should not have been a problem - it
happens with monotonous regularity - I just drop in a new disk, boot
from tape, and restore the latest backup.

This time it didn't work. The restore script reported numerous instances
of "file not found on tape". The system was (barely) bootable after
restore, but many files and directories were missing. I tried several
backup tapes with the same result, leading me to conclude the tape drive
had been writing unreadable backups for some time without reporting any
errors.

I tried restoring a backup from another system with identical hardware
and similar software configuration as I figured I could reconcile the
differences without too much difficulty. This worked, but I cannot
backup and restore the resulting system - I get the same "file not found
on tape" errors.

I've narrowed the issue down somewhat:

1. Backup tape from System B restores without error on System A
2. System A boots normally after restore, and appears to be a perfect
System B clone
3. Backup of System A immediately after restore completes without error
4. Attempt to restore System A from step 3 tape gives numerous "file not
found on tape" errors
5. Swap out the System A tape drive (6 times so far!) and repeat from
step 1 - same result!

So it seems to me I either have 6 tape drives that boot and read just
fine, but can't write a usable backup tape - or something else is
causing the problem. 6 tape drives with the same problem seems highly
unlikely. The backup script must be identical (since it was restored
from System B), as must the restore script (it's on the boot partition
of the backup tape), so WTF is going on here?

TIA

Triffid

Relevant Pages

  • Re: Dump/restore mystery (off topic)
    ... Triffid wrote: ... > from tape, and restore the latest backup. ... The restore script reported numerous instances ...
    (comp.unix.solaris)
  • Re: Dump/restore mystery (off topic)
    ... Triffid wrote: ... > from tape, and restore the latest backup. ... The restore script reported numerous instances ...
    (comp.unix.solaris)
  • Re: SBS Backup and RSM
    ... change creates uncertanties the day you have to do a full restore. ... I would use the NT backup information store backup, ... I greatly exceed the min requirements for SBS with both these ... tape drives all over the place and I don't have this problem with any ...
    (microsoft.public.windows.server.sbs)
  • Re: backup - how to?
    ... >> on IBM server and I'd like to backup system on streamer. ... > As far as streaming tapes are concerned, I did backups on a floppy tape ... I discovered Ecrix VXA tape drives. ... The only people for me are the mad ones -- the ones who are mad to live, ...
    (comp.os.linux.misc)
  • Re: Dump/restore mystery (off topic)
    ... >>from tape, and restore the latest backup. ... The restore script reported numerous instances ... I understand dump should ideally be run against unmounted file systems, ...
    (comp.unix.solaris)