Hi,

I have fixed the problem by adding the following lines to the backup
script.

     mt -f /dev/enst1 compress 0   # disable it
     mt -f /dev/enst1 blocksize 0  # variable size blocks
     mt -f /dev/enst1 density 21   # for 8500 format, use 0x15 (21)

I have not experimented enough to know which of these made the difference
but I suspect that it is setting the density. I assumed that the drive and
NetBSD would use either the 8500 format or the compressed 8500 format by
default. Was this assumption incorrect?

Thanks.

On Thu, 17 May 2001, Claude Marinier wrote:
> I previously posted about problems with dump to tape. The system is an
> Intel PD440FX, 128 MB memory, 8 GB main disk IDE, Eliant (Exabyte) tape
> drive SCSI narrow, 100 bps Ethernet, plain video. It runs NetBSD 1.5 and
> serves DNS, DHCP, SMTP. Last month, the backups started failing with pre-
> mature 'end of tape detected'. I tried using the B option with a value of
> 7000000 (unit is 1 KB blocks) which approximates the capacity of the
> Eliant (made by Exabyte, similar to 8505) when using 160 m cartridges.
>
> The change did not solve the problem but it is easier to work with total
> capacity than length and density.
>
> Early on, I added a Python 4 mm DAT drive to the SCSI chain and started
> doing backups to that drive.
>
> Now, the Python is failing with the same error: end of tape detected.
>
> Before this latest development, I thought that the Eliant was failing
> (i.e. I have a hardware problem). It seems unlikely that the Python has
> caught the same disease as the Eliant.
>
> Here is part of the backup script I am using with the Python.
>
> 	b=32
> 	B=2000000
> 	f=/dev/nrst0
> 	dump 0ubBf $b $B $f /
> 	dump 0ubBf $b $B $f /usr
> 	dump 0ubBf $b $B $f /var
> 	dump 0ubBf $b $B $f /home
> 	dump 0ubBf $b $B $f /var/mail
> 	mt -f /dev/rst0 offline
>
> Am I dealing with a software problem? or am I dealing with an environ-
> mental problem (i.e. contamination) ?

-- 
Claude Marinier, Information Technology Group    claude.marinier@dreo.dnd.ca
Defence Research Establishment Ottawa (DREO)    (613) 998-4901  FAX 998-2675
3701 Carling Avenue, Ottawa, Ontario  K1A 0Z4         http://www.dreo.dnd.ca