Cache Advice

[boxer74]

I have the following options for my cache pool, but can't device which would be best. Which would you choose and why? I run docker containers (plex, sab, etc.) and a Windows 10 VM with GPU passthrough as a workstation off the cache pool. For reference, my motherboard is the AsRock EP2C602. unRAID is used for media and VM's. My critical data is on a separate FreeNAS server. Data needed by docker containers from FreeNAS is NFS mounted using UD and passed to docker as 'Slave/RW' or 'Slave/RO'.

 

1. BTRFS RAID1 using pair of Intel 600p 1TB consumer NVME drives in PCIe 3.0 x4 adapters
2. BTRFS RAID10 using four Intel DC S3700 400GB enterprise SSD's connected to LSI 9211-8i (no trim support)
3. BTRFS RAID10 using four Intel DC S3700 400GB enterprise SSD's connected to motherboard (2 to Intel 602 chipset, 2 to Marvell controller, or all 4 to Marvell controller - possible reliability issues with Marvell controller but would gain trim support)
4. Some combination of the above with S3700's as cache pool for docker containers and maybe a single NVME for VM's through UD (but this would lose the redundancy).

 

I've been leaning towards option 1 to gain 200GB more usable cache space and while these NVME drives don't have much better write speed than the S3700's, they have much higher read speed rating. It would also clean up the cabling inside my case and I could possibly use a couple of the S3700's as SLOG devices in my FreeNAS machine, which is more inline with their design intent as write resilient SSD's.

 

I should clarify too that I own all the above drives, so there's no real cost consideration here.

 

What do you think?

[John_M]

Why don't you do some testing, since you already have the parts, and see what works best for your use case?

[JorgeB]

Don't use the Marvell controller, they are notoriously problematic on those boards.

[boxer74]

I currently have it setup with option 2. I'll run some tests and try option 1. I tend to agree about what I've heard of the Marvell controller.