I have put in systems with all SSDs, and systems with mixed set of SSDs and Hard Drives. I have found it best to run the TRCASPBAL and STRASPBAL on those disks so that the hot data goes to the SSDs. Yes, the system will perform better with just putting some SSDs in, but it will perform better if you optimize the data that you put on it. Meaning the data you access more.
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Bakutis, Becky
Sent: Wednesday, February 13, 2013 5:39 PM
To: Midrange Systems Technical Discussion
Subject: RE: SSD Best practices
We are going to start using SSD drives on a few systems in the near future. I did research the TRCASPBAL & STRASPBAL commands and was prepared to use them for data placement. My boss heard from a vendor that just loading SSD drives without worrying about 'hot data' will provide performance benefits also. Is this a true statement? Or will there be more bang for the buck to place the 'hot data' on these drives? I believe the plan for these systems was to replace all HDD drives with SSD drives. Thanks for pointing to your presentations.
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Sue Baker
Sent: Tuesday, February 12, 2013 5:20 PM
Subject: Re: SSD Best practices
On 2/11/2013 11:43 PM, Gad Miron wrote:
Beside handpicking hot items to (manually) move to these SSD disks are
there any proven automatic or semi automatic system procedures to do
it like TRCASPBAL / STRASPBAL(*HSM) etc.
You can programmatically run TRCASPBAL followed by STRASPBAL, if you want. I include a sample program in my presentations on SSD. URL www.ibm.com/support/techdocs and then search on my name to find the most recent version of the presentation.
Most people I talk with that wish to use balancing will trace during specific time periods each day and then run the STRASPBAL on Saturday or Sunday to move the data.
I know vendor plugs are frowned upon, but I would be remiss if I didn't offer the information that there is an IBM Power Systems Lab Services offering to discuss with you your performance challenges, analyze your data, and finally make recommendations on what data to flag as resident on SSD.