Re: Failed dumps with new amanda client

On Tue, 20 Jun 2006, Joshua Baker-LePain wrote:

> On Tue, 20 Jun 2006 at 4:27pm, up AT 3 DOT am wrote
>
> > On Tue, 20 Jun 2006, Joshua Baker-LePain wrote:
> >>
> >> I'd start by using amtapetype to test your new drive, both for hardware
> >> compression and native speed.  I'd also look at adding a holding disk to
> >> your config, if at all possible.
> >
> > Thanks for the response.  Here's what I get with amtapetype:
> >
> > su-2.05a$ amtapetype -f /dev/nrsa0
>
> amtapetype runs better when given an estimate of the tapelength.
>
> > Writing 256 Mbyte   compresseable data:  92 sec
> > Writing 256 Mbyte uncompresseable data:  90 sec
>
> That's a check to see if hardware compression is enabled -- it isn't.
> That's good.
>
> > Estimated time to write 2 * 1024 Mbyte: 720 sec = 0 h 12 min
> > wrote 763218 32Kb blocks in 2334 files in 13153 seconds (short write)
>
> 763218*32KiB = 23.3GiB, /13153s = 1857 KiB/s.  Those are pretty similar to
> what your network dumps were getting.  So it's your tape drive and/or
> tapes that are the issue.  Again, I have no experience with DLT, but check
> your tapes to make sure they're really 35GB capacity.  Any problems with
> the SCSI chain?  Does the drive simply need to be cleaned?
>
> > It's going through another write at the moment, but I assume "short write"
> > means it isn't getting full capacity from the tape?  Not sure what those
>
> "short write" simply means that it tried to write another 32KB block, and
> there wasn't room on the tape for it.  That's what happens when you hit
> EOT.

Here's the complete report, now that it finally finished:

su-2.05a$ amtapetype -f /dev/nrsa0
Writing 256 Mbyte   compresseable data:  92 sec
Writing 256 Mbyte uncompresseable data:  90 sec
Estimated time to write 2 * 1024 Mbyte: 720 sec = 0 h 12 min
wrote 763218 32Kb blocks in 2334 files in 13153 seconds (short write)
wrote 757298 32Kb blocks in 4646 files in 20125 seconds (short write)
define tapetype unknown-tapetype {
    comment "just produced by tapetype prog (hardware compression off)"
    length 24034 mbytes
    filemark 81 kbytes
    speed 1530 kps
}

Does this mean that this 35GB uncompressed tape is only yeilding 24GB?
The mt program recognises it as a 35GB tape:

su-2.05a$ mt status
Mode      Density              Blocksize      bpi      Compression
Current:  0x1b:DLTapeIV(35GB)    variable       85937    IDRC
---------available modes---------
0:        0x1b:DLTapeIV(35GB)    variable       85937    IDRC
1:        0x1b:DLTapeIV(35GB)    variable       85937    IDRC
2:        0x1b:DLTapeIV(35GB)    variable       85937    IDRC
3:        0x1b:DLTapeIV(35GB)    variable       85937    IDRC
---------------------------------
Current Driver State: at rest.
---------------------------------
File Number: 0  Record Number: 0        Residual Count 0

BTW, with DLT, the 2000, 4000 and 7000 all use the same actual media, DLT
IV.

James Smallacombe                     PlantageNet, Inc. CEO and Janitor
up AT 3 DOT am                                                      http://3.am
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