Antwort: Virtual Volumes...

Hi Allen,
my setup is 2 x TSM 4.2.1.9
2 x Win2k SP3
2 x ADIC 100 LTO

We have a server to server crosslink to backup data from one Adic100 to the
other not utillizing library sharing. We set up 10 GB virtual volumes on each
server. One ba stg runs daily to backup the data to cross having two mountpoints
each and reclamation set to 50%. One server makes Domino backups
the other file. The funny thing is though, although the virtual volumes are set
to 10GB the "notes" server creates a large number of virtual volumes that have
an estimated capacity of 100kB, 1MB, 2MB, on the same pysical LTO tape on the
destination server. The "file" server creates 10GB volumes and fills them
between 80% and 100%. I seem to think that the small virtual volumes have to do
with the fact that notes transaction logs are backed up into the copy stg as
well. On the other hand, due to expiration etc, when a stg pysical volume on the
destination server becomes "free" the status doesn't  change from private to
scratch, but stays private with no data in it and no association to the stg that
was created on the destination server to host the virtual volume. The tape was
used last by the stg that was created on the destination server.
We also have several other TSM servers that do a db backup to virtuel volumes
where everything is ok.
Have you / anyone seen anything like that, a call with Tivoli didn't help.

 Best Regards

Markus Veit








                                               An:      ADSM-L AT VM.MARIST DOT 
EDU
                                               Kopie:
                                               Thema:   Virtual Volumes...

             owner-adsm-l AT VM.MARIST DOT ED
             U
             Received :  03.09.2002
             17:04
             Bitte antworten an "Allen
             S. Rout"






Greetings all.  For those of you using virtual volumes, how large do you make
the volumes?  When I started doing this, I had the following opinions:

+ The server volumes should be significantly smaller than the remote physical
  storage.

It would be a real pain for most of the virtual volumes to be spread over
different tapes; multiple physical mounts for each virtual mount?  Ugh.


+ The server volumes should be large enough not to be a huge load.

Each virtual volume is a "file" on the hosting server.  For each TB of data,
that's 1000 files if volumes are 1G; actually probably more like 1300, with
reclamation at 50%.  You certainly don't want them as small as 100M.


I selected 1GB for my virtual volumes, but am starting to re-think the issue,
maybe going for 10G or so.

Anyone want to share thought processes?


- Allen S. Rout