Change cache after creation?

[WolfR1der]

Is there a way to change the cache settings after creating the device? Our currently clustered devices each have only 256MB system cache and no SSD cache. We would like to bump that up on the RAM cache and are considering installing dedicated SSDs on each of the two cluster servers to get better performance out of our cluster.

[Boris (staff)]

It is possible to change these settings.
For L1 cache manipulations, check this article: https://knowledgebase.starwindsoftware. ... -l1-cache/
For L2 cache manipulations, this will be useful: https://knowledgebase.starwindsoftware. ... dance/661/

[WolfR1der]

Thanks. Which service needs to be restarted when changing cache? Your article states that the service needs to be restarted but not which service. There are four 'Starwinds' labeled services on my servers. Virtual SAN or Cluster Service would be my guess.

Also which SWDSK file do I work with? There are two and each has that setting within it. One is Disk1.swdsk and the other is Disk1_HA.swdsk.

[Oleg(staff)]

You should make changes to *.swdsk file, not HA, for the StarWind device on which you want to add cache, this file is located in the folder with one, on each node.
You should make sure if StarWind devices are synchronized, stop StarWind on one side, make changes to *.swdsk file, start StarWind, check if everything is synchronized and then proceed to another node.

[WolfR1der]

Thanks.

Is there a significant speed increase adding an L2 cache? Or would simply adding more L1 cache be the best option?

[Oleg(staff)]

L2 cache works in Write Through mode. So, with adding L2 cache, you will increase only read operations. If it works for you, you can add.
If you adding cache, our recommendations are following:
-1 Gb of L1 cache per 1 Tb of StarWind drive;
-if you plan to use L2 cache, the size of L2 cache (SSD cache) should be around 10% of StarWind drive size.

Also, you can check recommended RAID array settings for underlying storage there.