On maandag, september 2, 2002, at 11:26 , Daniel Sparrman wrote:

Hi

The large disks you are talking about, are you meaning large as 36GB,
72GB
an so on, or are you talking about LUN-sizes?

Disk size, 72 GB or so....

In a shark, you can have very large LUN:s, but they will consist of a
large number of smaller SSA-based hard drives. This means that you will
not have a performance impact on the disks.

I know, I also know that you will have performance impact on your disks.
I noticed that especially the IBM ssa raid controller (4-P)  gives very
bad performance on any kind of raid. I don't have a shark, so I can't
talk about it's raid controller. Having eg. both the db volumes and the
logvolumes on the same raidgroup will for sure give you very bad
performance on the disks. Also, I don't think it's a good idea to have a
database (or log) spread across multiple partitions on the same
raidgroup. TSM will try to do 'smart' load balancing, which will
decrease performance in that case since the disks will have to do more
seeks.

---
Met vriendelijke groeten,

Remco Post

SARA - Stichting Academisch Rekencentrum Amsterdam    http://www.sara.nl
High Performance Computing  Tel. +31 20 592 8008    Fax. +31 20 668 3167
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