Primocache with Drivepool and SSD Optimizer Topic is solved

[Matters]

Apologize if this is a dumb question but just started trying Primocache out as I have a couple spare external NVME drives I can use (running on a USB 5gbps interface). I read through the documentation but its still kinda unclear to me as I haven't been using it very long.

I've been using Drivepool on a home server for years (movies etc). I use the SSD optimizer plugin which causes the files to first land on one of a couple of 2.5" SSDs before later being transferred to one of the HDDs for long term storage.

I set two Primocache tasks: L1 only for the SSDs and L2 for the HDDs using the external nvme,

Is there any benefit to using a L2 external NVME for both read and writing? I don't see how writing would benefit speed as the files already go from one of my SSDs to a HDD and the HDDs don't really swap files between themselves. The HDD drive speed being the rate limited step.

My other question is, am I able to use two NVME drives for the L2 cache? One for read and one for write so a drive doesn't get slowed down doing R/W at the same time? Edit: Only appears possible to use one L2 per task.

Finally I'm awaiting another HDD drive to set up Snapraid. Would Primo interfer with syncing?

Thanks!

Edited for clarity

[Support]

Is there any benefit to using a L2 external NVME for both read and writing? I don't see how writing would benefit speed as the files already go from one of my SSDs to a HDD and the HDDs don't really swap files between themselves. The HDD drive speed being the rate limited step.

Do you mean using an external nvme ssd as L2 cache for the SSDs? It might help if these SSDs are SATA SSDs. Otherwise there is no need to do this.

My other question is, am I able to use two NVME drives for the L2 cache? One for read and one for write so a drive doesn't get slowed down doing R/W at the same time? Edit: Only appears possible to use one L2 per task.

No, PrimoCache can only support one volume as a L2 cache in one task. It can support a RAID volume combining multiple drives as L2 cache. But I think this is still not what you want.

Finally I'm awaiting another HDD drive to set up Snapraid. Would Primo interfer with syncing?

Sorry we haven't fully tested compatibility with SanpRaid yet. To be on the safe side, you may also pause the cache when SanpRaid runs.

[Matters]

Thanks!

What I ended up doing was swapping in the spare 2TB NVME in the M2 slot in the PC instead of using it as an external. I made a small windows partition and formatted the rest as an L2.

I wasn't impressed with the speed using Drivepool's SSD optimizer since the external drives (SSDs and HDDS) only run on 5gbps interface (limitation of the NUC I'm using). I set a Read/Write L1 and L2 for both the external SSDs and HDDs and now everythings speedy. It definitely warranted a license purchase. I can probably ditch the SSDs now since they don't offer much benefit as a landing zone but I'll keep it as it is for now. I assume a file first being downloaded to the SSDs will store in the cache and then when its moved later to the HDDs utilize that cache for the transfer?

[Support]

I set a Read/Write L1 and L2 for both the external SSDs and HDDs and now everythings speedy.

I'm glad to hear PrimoCache helps.

I assume a file first being downloaded to the SSDs will store in the cache and then when its moved later to the HDDs utilize that cache for the transfer?

Yes, as long as you enable L2 cache and defer-write. For more information, please see
https://kb.romexsoftware.com/en-us/2-pr ... te-writing
https://www.romexsoftware.com/en-us/pri ... write.html