Cache Pool worth it in this senario?

[jvorn]

Hey all, I used to use an ancient Samsung 250 GB SSD as my cache, but when I rebuilt my server I sprung for a 1 TB NVMe SSD.  Not wanting to throw the Samsung away, I just pooled them (I'm sure you know where this is going).  Well now I realize my mistake, since RAID 1 is default I've been essentially only using 250 GB of my 1 TB drive.  My question is it still worth it to keep the old 250 GB drive and do either RAID 0 or Single?  There's quite a speed gap between the two, I don't want to hamper the NVMe.  I could just remove the 250 GB and roll with just the NVMe drive. Thoughts appreciated!

Edited April 10, 2020 by jvorn

[JorgeB]

It's up to you, but note that raid0 will only use 250GB from each device, so to keep both single profile is the best option, it just depends if those extra 250GB are worth it.

[itimpi]

Are you using many VM’s or Docker containers?    If so it might be worth keeping the 250Gb SSD as a cache drive and use the 1TB drive via the Unassigned Devices plugin for storing VM images to get maximum performance.  Of course the converse is also possible, and you should select the option that best supports your work pattern.

 

if you go such a route then you will not have redundancy on the SSD’s but you could look at the CA Backup and VM backup plugins as a way of automatically backing their contents up to the array at intervals of your choosing.

[jvorn]

Thanks guys! I went with single for now.  I think Ill add another NVMe down the line for true Raid 1 later.