Disk Cache Option

[JSunny]

Hey,

i am using FreeNAS with a i3 and an external hardware raid station. i have also added a SSD.
My first attempt was to use the SSD as Swap but then i saw the Cache option during the setup of a volume.

If i would include my SSD as cache, how exactly would that work?
If my volume is encrypted, does the cache breaks the chain of encryption or are the data also encrypted on the cache?
Would it be better to use a SSD as Swap or as the Cache option? (maybe a different algorithm?)

Thank you for your help.

best regards
JSunny

 

[dlavigne]

That option lets you create a ZFS read cache, which is described in http://sphinx.freenas.org/freenas.html#zfs-primer.

It would have no affect on encryption as the encryption FreeNAS uses only protects against stolen disks. Once the volume is unlocked at boot time, the data is readily accessible. See http://sphinx.freenas.org/freenas.html#encryption for a longer description.

 

[cyberjock]

You should read my noobie guide. L2ARCs don't always make your system faster and they can in fact make it slower. In short, if you don't *know* you need one, then you shouldn't have one.