Re: How to check if TSM is using hw compression?

Bernd,

The device class is the only place within TSM where you can affect
compression.

It's been a long time since I've used a drive without compression, but I
believe you'd see a more consistent capacity with compression turned off.
If you were consistently getting 37G, I could believe that compression was
turned off, but you have tapes with more and less than that.

If this is a copy storage pool for your primary server, what are the server
to server device class settings?

A "query content <volume_number> f=d" will show you the stored size of a
file on tape.

Bill Smoldt
STORServer, Inc.

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU]On Behalf Of
Bernd Schemmer
Sent: Saturday, September 06, 2003 9:53 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: How to check if TSM is using hw compression?


Hello,

Using TSM 5.1.6.2 on Solaris 8 with a Sun L20 Tape Library (using DLT8000
drives) how can I check if TSM uses the hardware compression of the drives?

We use the TSM driver to access the drives (so there's no special driver
for using the drives in compression mode). The only way to configure hw
compression in TSM I found is to configure the approbate drive format in
the device class (DLT35C or DLT40C) (Is there another way to configure
the hardware compression?) I did this but TSM still only writes about
37.000 MB on 35/70 GB DLT IV Tape. This is independent from the kind of
data written. We use the server only for a Copy Storage Pool of our
primary server. The data to backup is mostly Oracle DBs, Filesystem
backups, Domino Data backups, etc.

Some TSM output:

tsm: TSM2>q volume

Volume Name               Storage      Device      Estimated    Pct   Volume
                           Pool Name    Class Name   Capacity   Util Status
                                                         (MB)
------------------------  -----------  ----------  ---------  ----- --------
/tsm/01/archive/archive-  ARCHIVEPOOL  DISK         20,000.0    0.0  On-Line
  pool_vol001.dsm
/tsm/01/backup/backuppo-  BACKUPPOOL   DISK         20,000.0    0.0  On-Line
  ol_vol001.dsm
ARZ00016                  LIBRARYL20   DEV1         38,621.3   94.1    Full
ARZ0003                   LIBRARYL20   DEV1         35,305.2  100.0    Full
ARZ0004                   LIBRARYL20   DEV1         71,680.0   19.4  Filling
ARZ0005                   LIBRARYL20   DEV1         31,060.1  100.0    Full
ARZ0006                   LIBRARYL20   DEV1         71,680.0   26.7  Filling
ARZ0011                   LIBRARYL20   DEV1         45,654.5  100.0    Full
ARZ0013                   LIBRARYL20   DEV1         37,968.0  100.0    Full
ARZ0014                   LIBRARYL20   DEV1         37,125.2  100.0    Full
ARZ0015                   LIBRARYL20   DEV1         33,276.5  100.0    Full
ARZ0016                   LIBRARYL20   DEV1         40,359.1  100.0    Full
ARZ0017                   LIBRARYL20   DEV1         38,636.0   99.7    Full
ARZ0018                   LIBRARYL20   DEV1         37,670.3  100.0    Full
ARZ0019                   LIBRARYL20   DEV1         37,165.9  100.0    Full
ARZ0021                   LIBRARYL20   DEV1         33,153.4  100.0    Full

tsm: TSM2>q devclass dev1 f=d

              Device Class Name: DEV1
         Device Access Strategy: Sequential
             Storage Pool Count: 1
                    Device Type: DLT
                         Format: DLT35C
          Est/Max Capacity (MB): 71,680.0
                    Mount Limit: 2
               Mount Wait (min): 60
          Mount Retention (min): 60
                   Label Prefix: ADSM
                        Library: L20
                      Directory:
                    Server Name:
                   Retry Period:
                 Retry Interval:
                         Shared:
Last Update by (administrator): ADMIN
          Last Update Date/Time: 09/04/03   12:13:27


Looking at this output I think, that TSM does not use the hardware
compression at all. Or am I wrong?


TIA

Bernd

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