I had to be root in order to change the defcompression setting using mt.

Thanks for your help thus far.

Nick
We'll see tomorrow morning what amanda does.
Paul Bijnens wrote:

On 2007-10-17 14:05, Nick Brockner wrote:

Thanks, I just did a "mt -f /dev/st0 compression 0", "defcompression 0" didn't seem to be valid for this device (or nst0), so I guess I'll just reboot to be sure compression is off on the drive.

I guess we'll see what happens tonight.

You did read, and understand:

http://tech.groups.yahoo.com/group/amanda-users/message/60030

  ?  (link mentioned in the wiki)

Because just those DAT drives have that problem (at least, that is where
I encountered them first).  I mean: it is NOT enough to disable
compression by that command above, because, that sets the mode only
for the next write to the drive.  However, amanda always first READS
the tape inserted to verify the label, and by doing that, the tapedrive
is set to whatever mode that the tape was written with. If that tape
was written in compressed mode, the drive is in compressed mode again.

A reboot will not help at all, it will just reset the tapedrive to
the default mode, but still subject to autochange mode the when reading
a tape.

To really verify if compression is off, you can use the command:

  amtapetype -c -f /dev/nst0

which takes only a few minutes.

Nick
Paul Bijnens wrote:

On 2007-10-16 16:18, Nick Brockner wrote:

Hi All,

I am using amanda 2.5.1p1, and I have just started seeing this (with the failing of the DLE that is currently on):

planner: Last full dump of <HOSTNAME1>:/home on tape overwritten in 1 run. taper: tape weekly-2/tape-3 kb 30827264 fm 28 writing file: No space left on device taper: retrying <HOSTNAME2>:/.0 on new tape due to: [writing file: No space left on device]

  taper: tape weekly-2/tape-6 kb 0 fm 0 [OK]

I am using DAT72, so I should be getting 36 G of usable space. Please help, as I can't get the spanning to work either, and when it tries to write to the next tape, it just dies for some reason. . .

I bet you are using the tape drive in hardware compression mode
and have Amanda let the data compress with software compression
as well.

The compression algorithm in DAT drives is stupid enough to not
detect uncompressable data, and hence blindly applying that compression
algorith to such data results in actually expanding the data by
about 20-30%.  That should acount for getting 30GB instead of 36 GB
data on the tape.

Solution:  disable the hardware compression on the tape drive.

http://wiki.zmanda.com/index.php/Hardware_compression