Corrie,

 Check the estimated capacity that is set on the 'Device Class' for the
tape. This might be set at less that the actual capacity of the cartridge
you are using and if I recall can impact the amount of data that TSM will
write to the physical device.

 - Brian




                   "Viljoen
                   Corrie *             To:     ADSM-L AT VM.MARIST DOT EDU
                   arivia.kom           cc:
                   (GP)"                Subject:     FW: TSM data on tape
                   <CorrieV@DATA
                   VIA.CO.ZA>
                   Sent by:
                   "ADSM: Dist
                   Stor Manager"
                   <ADSM-L AT VM DOT MA
                   RIST.EDU>


                   03/22/2001
                   08:13 AM
                   Please
                   respond to
                   "ADSM: Dist
                   Stor Manager"






From:  Viljoen Corrie                * arivia.kom (GP)
Sent:  Thursday, March 22, 2001 2:42 PM
To:  Moodley Desigan         * arivia.kom (GP)
Subject:  TSM data on tape

We are using 3480 / 3490 and 3490E tape technology with Silverton and
Timberline drives for storing data via TSM software. We are experiencing
problems for a while now with running out of tapes in all our storage pools
and it is growing by the day. We are already occupying at least more than
5000 tapes in our NEARLINES. The reclamation processes are running
everyday.
There is a situation where I looked at all my volumes and realized that
only
a maximum of 900 MB is stored on a 2.3 GB tape. TSM then marks the tape as
full. While it is writing it shows at a stage that only 35% odd is utilized
on the 2.3 GB tape because it is 900 MB of 2.3 GB but then it stops and
marks the tape as full. The message is ANR5334W to say that the end of the
volume was reached before the maximum capacity of the tape which is suppose
to be 2.3 GB at least. We tested the same volume by dumping a disc pack,
which is 98% utilized, of at least 2.3 GB to the tape and it stored the
full
pack on the 1 volume which says the technology is 100%, 3490E.  Then we
stopped compression on the nodes as well as the device classes in TSM to
let
compression take place on the drive only.  We did a test backup thereafter.
The same scenario happened with only 900 MB stored. We are loosing over 1.4
GB per volume which is unacceptable. Any suggestions on where to look now
or
what to change to ensure we use all of the 2.3 GB on the 3490E technology?
This will solve 99% of our tape headaches and will minimize the tape usage
dramatically.
Regards

Corrie Viljoen
CorrieV AT Datavia.co DOT za <mailto:CorrieV AT Datavia.co DOT za>
(w) 359-1731
083 294 2405