Awhile back I was having some tape problems. I have done some experimentation
since then and have come up with this:
Setup
- Ecrix VXA with VXA-17 tapes
- tape block size 0
Original problem
- AMANDA claims to write to tapes without error
- trying to restore using any method (dd, amrecover, amrestore) fails
with hardware error: Additional sense indicates Recorded entity not found
or: Additional sense indicates Unrecovered read error
- I discovered that these hardware errors occur when seeking a file that
does not exist.
Test
- filtered out tapes that do not produce errors
- read header off of the remaining tapes,
I think in all cases, but one, I was able to read the headers
- extracted header and saved to file
- tar cf /dev/nst0 /multiple_paths (totalling 525MB)
- mt rewind
- tar tvf /dev/nst0
- mt rewind and dd'ed the header back
- all "bad" tapes pass this test with 0 failures!
So, why is it when AMANDA backed up data to some of these tapes, I can
no longer read them back and get "hardware" errors?
Did the tapes lose some sort of formatting?
Did AMANDA screw something up while writing?
What other kinds of tests can I perform? with AMANDA?
Any other suggestions?
BTW, Since it seems AMANDA uses 32k blocks on the tape, I am going
to change block size from 0 (which excrix recommends for some reason) to 32k.
Thanks for any info.
--
Robert Dale
Digital Mission LLC
