I have been asked to evaluate the use of copypool-only TSM servers built on 
virtual machines. 

Virtual machines on ESX can't do I/O to tape devices, but the source server for 
a server-to-server copy pool does not need to do I/O to tape devices. It sends 
its files to the target TSM server which does the tape I/O.  So, potentially, 
several TSM servers built on virtual machines could send virtual volumes to one 
physical TSM server target with tape I/O capability. Primary pools would be 
defined on the source servers, but they would be marked unavailable permanently.

Each TSM server on a virtual machine would have two copy pools: one on-site and 
the other off-site; instead of an on-site primary pool and an off-site copy 
pool.  

The reason for doing this would be; to divide the backup load into smaller 
chunks across more TSM servers, to avoid buying more physical servers, and to 
share tape drives without using a Library Manager. 

A detriment of this setup would be that reclamation of the copypools would be 
degraded with no primary tape pools to read from. 

Are there other obvious or subtle problems with this idea? Or, is it 
brilliant?...   

Which copypool would restore files come from? How would that be managed?

Our TSM license is based on TB in primary storage, so extra licenses are not a 
factor. 

Please, don't be shy.

Thank you,
Keith Arbogast    
Indiana University