A sample illustrates how to follow configuration guidelines for storage pools that use the DISK device class and DS5000 series disks.
Remember: Ensure that the server database, recovery
logs, and storage pools are on different disks.
Sample layout
In this sample, the Fibre Channel or Serial Advanced Technology Attachment (SATA) disks in a DS5000 series system are configured with these characteristics:- The disks are configured in a 4 + 1 RAID 5 array. Stripe size is 256 KB.
- Four logical volumes are defined on the disks. In Tivoli® Storage Manager, these volumes are defined as four storage pool volumes for a random-access (DISK) storage pool.
Figure 1. Storage pool layout
with 4 + 1 RAID 5
The layout has the following advantages:
- The layout follows the stripe size recommendation (full stripe write).
- The layout follows the guideline that an n + 1 RAID array has no more than n volumes.
The disadvantage is that there is a performance cost for the write-parity operations. The write-parity operations might not cause a performance problem if the cache for the disk system is adequate.