Re: Best Practices DISK for DB, LOG, and STGPOOL && JigSaw Puzzle

On Sep 14, 2006, at 4:44 AM, Bernaldo de Quiros, Iban 1 wrote:

Hi Richard,

It is the first time that I do a disk assignment for TSM.
As you said, I have review the documentation there are really goodadvices, but it did not say anything about volumes sizes... Forexample use 10 physical disk, on each of them create a 10 GBpartition for the database... To have 100 GB...
So I do not know what volume size(partition to Spread DB, LOG,STGPOOL) will be suitable for DB, LOG, and STGPOOL.
What volume size will be suitable for a TSM 5.3 installation ¿?

Thanks in advance !!


Hi, Iban -

The guiding principle for the major random access server element, itsdatabase, is that you give it as many disk accessors (arms, spindles)as you can afford, where RAID striping tends to work best. Partitionsize is not the issue here, but distribution of I/O. Size theaggregate size to satisfy your current needs, and either create alike reserve, or make your design extensible, to satisfy growth demands.

Disk storage pools are also random access, but with much larger unitwrite sizes, so spreading I/O is not as much a factor, and sizingtends to be large.

The Recovery Log is essentially a sequentially written area, sospreading I/O is not a factor.

Be mindful of I/O path capacity in your planning: having high-performance disks won't help if the path to them is congested.Spread I/O over multiple host adapters, as can be computed from loadfactors. Some computers have multiple I/O planars (buses), where youwould want to avoid concentrating the host adapters in one planar,which would result in needless constriction and imbalance.

Much of this is standard computer planning, knowing thecharacteristics of the I/O to the various TSM areas. And rememberthat nothing hampers a caching server, such as TSM is in its databasehandling, like inadequate real memory, so don't skimp there.


   Richard Sims