It sounds like ADP's are disk only (using FILE device type)... is this
true?  How are ADP's "kept" active-only... is it automatic, or do you have
to run reclaims to remove inactive versions?  Or do you just completely
rebuild them periodically?

Based on this description, I'm not sure this feature will be all that
valuable...

Robin Sharpe
Berlex Labs



             Kelly Lipp
             <lipp@STORSERVER.
             COM>                                                       To
             Sent by: "ADSM:           ADSM-L AT VM.MARIST DOT EDU
             Dist Stor                                                  cc
             Manager"
             <[email protected]                                     Subject
             .EDU>                     FW: Implementation of Active Only
                                       Pools in TSM V5.4

             02/04/2007 01:37
             PM


             Please respond to
             "ADSM: Dist Stor
                 Manager"
             <[email protected]
                   .EDU>






Folks,

I asked a question of TSM development regarding Active Data Pools (ADP)
and received this excellent explanation.  I think you will find it
interesting.

The one thing that escaped my attention in the documentation is the
preference for restore choosing an ADP if one exists rather than a
primary or standard copy pool.

Thanks,

Kelly J. Lipp
VP Manufacturing & CTO
STORServer, Inc.
485-B Elkton Drive
Colorado Springs, CO 80907
719-266-8777
lipp AT storserver DOT com


________________________________

Active data pools (ADPs) represent a new type of storage pool, in
addition to primary and copy pools. ADPs were designed to meet the
following requirements.

1.           Improved restore performance. ADPs can be used with FILE
storage
pools to allow rapid client restores. If available, files will
preferentially be restored from a FILE ADP rather than a primary or copy
pool. There is also some benefit when performing server operations such
as GENERATE BACKUPSET.
2.           Reduced resources for maintaining copy pools. In addition to
being used for client restores, ADPs can also be used for storage pool
or volume restore operations. Since an ADP only contains active data,
the number of tapes is smaller than for a copy pool. Many customers want
to be able to move tape volumes with only active data offsite for DR
purposes and ADPs allow them to do so. By storing only active data, the
number of offsite tapes is reduced as is the effort to manage those
offsite tapes.
3.           Reduced size of disk staging pools. Keeping only active
versions
of data in an ADP reduces the size of the disk pool as compared to
keeping both active and inactive data in a copy pool.
4.           Reduced data movement. This requirement stems from customers
needing to stage data before performing client restore. Staging data
required active and inactive data to be moved to disk before the store
began. By keeping only active data, ADPs can eliminate the need for
staging data to disk before restore.


As an alternate design, TSM development also considered implementation
of active-only primary pools. This implementation would not have
supported restore of storage pools or volumes from the active-only
primary volumes nor would it have facilitated movement of those
active-only volumes to an offsite location. There were also significant
technical issues involving migration (inactive data could not be removed
from the active-only pool until it had been migrated) and with storage
pool backup (backup from an active-only primary pool to a copy pool
could mean that inactive files were not stored in the copy pool).