Re: Hardware compression has stopped working on 3570 drives

Eric,

this looks really strange. have you also tried to define a devclass with
recording format 3570C ?
( just a try )

herfried




Eric Winters <ewinters AT AU1.IBM DOT COM>@VM.MARIST.EDU> on 17.10.2001 08:05:06

Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>

Sent by:  "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>


To:   ADSM-L AT VM.MARIST DOT EDU
cc:

Subject:  Hardware compression has stopped working on 3570 drives


Dear TSM Community,

I have a situation in which I appear to have lost hardware compression on
both my 3570-C drives. We recently had one of two tape drives in a 3575
replaced, and since then I'm only getting 5 GB a tape, in spite of my
device class being set to format=drive (not that I have changed this). I do
not compress at the client.

Here are the headlines;
TSM Client is at 4.1.3.0
TSM Server is at 4.1.4.1
The drives are enabled for hardware compression (lsattr -El rmt0 shows
"Hardware enabled for compression: TRUE")
Atape.driver has been updated to 6.1.9
The 3570 Firmware has been updated to 5468
I have green 3570 tapes.
I have deleted the drives in TSM, deleted the devices in aix, recreated the
devices, redefined the drives.
Backing up approx 1GB with dsmc sel and no software compression utilises
20% of a tape.
Backing up approx 1 GB with dsmc sel and software compression (reporting
50% compression) utilises 10% of a tape. So I know the data is
compressable.
The devclass has a setting of FORMAT=DRIVE. I've tried making a new device
class with a new tape storage pool and backing up to that with TSM but
there's no relief - I'm still only getting 5 GB per tape for data which has
NOT been compressed by the client.
I've just used tar to back up 12 GB of data successfully to one of the
drives - so it looks like TSM is the problem.

Any ideas? As a consequence of this problem my scratch tapes have rapidly
been consumed and I could do with a brilliant suggestion.

Thanks in advance.

Eric Winters






****************************************************************************

The information contained in this transmission, which may be
confidential and proprietary, is only for the intended recipients.
Unauthorized use is strictly prohibited. If you receive this
transmission in error, please notify me immediately by telephone
or electronic mail and confirm that you deleted this transmission
and the reply from your electronic mail system.
****************************************************************************