TrueNAS VM - using vdisk for LOG cache.

[Gerard Oedzes]

Hallo all,

Short question about my TrueNAS vm.

According to this video: https://www.youtube.com/watch?v=M4DLChRXJog cache for log is speeding-up the performance.
I dont have a complete nvme drive left to passtrough but could or should i use an virtual-disk for this job?

Thnx in advance!

 

[Einar Stenberg]

Greatly depends on what kind of storage medium is backing the vdisk i would say.
If your other disks are hdd, and the storage you want to use for the vdisk is ssd, then you should see some perfomance improvment (depending on your workload also)

Though in my experience, adding caches in truenas greatly increases the complexity of your setup, and risk of something going wrong if not done properly. (And if the workload does not REALLY need it it is hardly worth the tradeoff)
So if it read performance you are after I would just go the route of adding a bit more ram for caching instead maybe.