2011-03-07 09:50 AM - last edited on 2014-09-26 12:18 PM by allison
I thought Flexscale was needed to tune / enable PAM, however I am being told that Flexscale is legacy and I need Flashcache with PAM II?
Pls could someone explain the difference between these components?
Also, do the license options (flexscale or flashcache) come with the hardware or do they need to be purchased in addition to the card?
2011-03-07 09:56 AM
PAM or PAM I is the 1st generation hardware card to supplement read cache. 16GB. Requres a Flexscale license.
PAM II or Flashcache is the 2nd generation hardware card to supplement read cache. 256\512GB. Requires a PAMii license.
Both Certain tuning parameters can be set using system options using options flexscale.xxx
2011-03-07 12:26 PM
Yes FlashCache and PAMII are the same thing. It is due to technology used and marketing.
The FlexScale license is no longer used, but to tune PAMI or PAMII you still use the flexscale options.
The systems that support PAMI support PAMII, so stating the FlexScale is no longer used is mostly correct from a licensing and hardware perspective.
Please read the following for more information:
2011-03-08 07:13 AM
Either shutdown the controllers or perform a cf takeover\giveback scenario and insert the PAM\FlashCache cards.
Install the license with license add XXXXXX
Configure Flexscale with:
Let it sit for a few days and then evaluate your working set size during peak or daytime usage:
stats show -p flexscale-access –i 1 –n 100
This is where you might need some help. You will need to review the current usage, cache hit and cache misses over the period of time and determine if the working set of the data is too great for the currently installed PAM card. If it is then you back the normal data blocks to off, otherwise leave it as is. Odds are that leaving normal data blocks on will be fine. It is highly unlikely that you will need to enable lopri blocks.