Hello,

We have a TSM Server 5.3.2.1 on z/Linux with a 3494 Library and 3592
Tape drives.

In the 3592 device class I have used the format=DRIVE option (see
below). How can I find out if the data on the volumes is written with
drive compression?
The average capacity of my volumes is 430GB (> native 300GB). Now I'm
not sure if this is due to client compression or due to drive
compression.
May it cause any problems with existing volumes if I change the format
option from drive to 3592c?

What are real life compression ratios for 3592 Tape Drives ?

select avg(EST_CAPACITY_MB) from volumes where status='FULL'-
            429021,75045045045045
select max(EST_CAPACITY_MB) from volumes
            605664,4

thanks,
Volker

Configuration
--------------
tsm: TSMSERV>q devcl devc_3592 f=d
             Device Class Name: DEVC_3592
        Device Access Strategy: Sequential
            Storage Pool Count: 5
                   Device Type: 3592
                        Format: DRIVE
         Est/Max Capacity (MB): 460,800.0
                   Mount Limit: DRIVES
              Mount Wait (min): 120
         Mount Retention (min): 5
                  Label Prefix: ADSM
                       Library: ATL3494
                     Directory:
                   Server Name:
                  Retry Period:
                Retry Interval:
                        Shared:
            High-level Address:
              Minimum Capacity:
                          WORM: No
               Scaled Capacity: 100
Last Update by (administrator):
         Last Update Date/Time: 03/14/05   10:17:02

tsm: TSMSERV>q drive  f=d
                                Library Name: ATL3494
                                  Drive Name: DRIVE1
                                 Device Type: 3592
                                     On-Line: Yes
                                Read Formats: 3592C,3592
                               Write Formats: 3592C,3592
                                     Element:
                                 Drive State: EMPTY
                                 Volume Name:
                                Allocated to: