ZFS Cache and Plugins

[SparJar]

I have searched for a bit but couldn't find an answer.

I run a Minecraft server on my FreeNAS box and since I just updated to 11.3 I was wondering if Jails/Plugins will use ZFS cache so that the server could run a little better than on the spinning drives it was running on before. If it doesn't by default is there a way to force it to? I have plenty of extra RAM that ZFS started using for cache when I upgraded it, but I don't know where to check what services are using it.

I am terrible at stating questions, so I hope this makes sense.


Hardware:
Dell r510 chassis
Dual 12-core Xeon X5670
96GB RAM
8 x 2TB 7200 RPM

 

[Patrick M. Hausen]

The cache is used on a per block basis so if your application accesses the disk the data will be cached. It uses a mixed MRU and MFU strategy and tries to balance both for best performance. There is no mechanism assigning cache to particular applications. The "ZFS" section in "Reporting" will tell you more details. If willing to set up a graphite compatible time series db and e.g. Grafana, one can get even more detail:

 

[SparJar]

The cache is used on a per block basis so if your application accesses the disk the data will be cached. It uses a mixed MRU and MFU strategy and tries to balance both for best performance. There is no mechanism assigning cache to particular applications. The "ZFS" section in "Reporting" will tell you more details. If willing to set up a graphite compatible time series db and e.g. Grafana, one can get even more detail:

Perfect! Thanks for the quick, and thorough reply!

 

[ornias]

Some applications in Jails might have features that allow you to cache more content in ram...
Like Nextcloud using Redis or MariaDB storing huge chunks for database in-ram.