Virtual Volume Weirdness

[DazRaz]

Hi,

I have about 50 remote TSM servers which uses virtual volumes on a central TSM server for offsite copy of data.

One of these servers is doing something I don't understand. If I look at the occupancy of the storage pools, I get this.

STGPOOL_NAME                                   OCCUPANCY
------------------     ---------------------------------
BACKUPPOOL                                      19231.24
OFFSITEPOOL                                      6876.10
OFFSITE_CHC                                      6872.90

The OFFSITEPOOL is local, the OFFSITE_CHC is virtual volume pool on the central server.

If I look at settings for the OFFSITE_CHC, I get this.

               Storage Pool Name: OFFSITE_CHC
               Storage Pool Type: Copy
               Device Class Name: OFFSITE_CHC
              Estimated Capacity: 11 G
              Space Trigger Util:
                        Pct Util: 62.3
                        Pct Migr:
                     Pct Logical: 99.7
                    High Mig Pct:
                     Low Mig Pct:
                 Migration Delay:
              Migration Continue:
             Migration Processes:
           Reclamation Processes: 1
               Next Storage Pool:
            Reclaim Storage Pool:
          Maximum Size Threshold:
                          Access: Read/Write
                     Description:
               Overflow Location:
           Cache Migrated Files?:
                      Collocate?: No
           Reclamation Threshold: 99
       Offsite Reclamation Limit: No Limit
 Maximum Scratch Volumes Allowed: 660
  Number of Scratch Volumes Used: 618
   Delay Period for Volume Reuse: 0 Day(s)
          Migration in Progress?:
            Amount Migrated (MB):
Elapsed Migration Time (seconds):
        Reclamation in Progress?: No
  Last Update by (administrator): ADMIN
           Last Update Date/Time: 07/13/09   11:00:57
        Storage Pool Data Format: Native
            Copy Storage Pool(s):
         Continue Copy on Error?:
                        CRC Data: No
                Reclamation Type: Threshold

And the devclass for the virtual volumes is as follows

             Device Class Name: OFFSITE_CHC
        Device Access Strategy: Sequential
            Storage Pool Count: 1
                   Device Type: SERVER
                        Format:
         Est/Max Capacity (MB): 500.0
                   Mount Limit: 2
              Mount Wait (min):
         Mount Retention (min): 2
                  Label Prefix: ADSM
                  Drive Letter:
                       Library:
                     Directory:
                   Server Name: CHCTSM01
                  Retry Period: 10
                Retry Interval: 30
                      Twosided:
                        Shared:
            High-level Address:
              Minimum Capacity:
                          WORM: No
               Scaled Capacity:
Last Update by (administrator): ADMIN
         Last Update Date/Time: 02/27/09   08:41:52

The problem is the 618 volumes in use. This storage pool should have a capacity of 330 GB but the 'q stg' shows a capacity of 11GB. The majority of the virtual vols show as 100% full but if they are 500MB in size, they can't be full.

I picked a volume which was last written to a year ago and queried the contents. It had one file in it with a size of 462KB. I deleted the volume and re-ran the backup of the storage pool. One new virtual volume was created which shows as 100% full.

Any ideas what is going on here?

Cheers

 

[DazRaz]

Ok, I think I've worked it out. The 500MB for the offsite_chc is for estimation purposes only. If the backup stg job only backs up a 2K file, it creates a 2k file on the other server and the virtual volume shows as 100% full. The virtual volumes are not 500MB in size - my bad!