ZFS cache and consumer SSD

[Lebowski89]

Hi all,

 

I've been reading (only a little) into Proxmox lately, and the one thing I've noticed is that those recommending SSD/NVME drives recommend enterprise grade / data-center level drives, as ZFS + Proxmox can write massive amounts to your drive to the point that it could easily use up the life of a consumer SSD. When I think about the typical user of UnRaid, they're usually one-step up from those running your prebuilt consumer NAS (Synology, etc) and have an array that would consist of some WD Red, Iron Wolf, maybe some Exos, frequently shucked Barracuda Pro, and so on. With the main requirement being CMR and not SMR. For SSD/NVME, I would think the typical UnRaid user would be throwing in consumer SSD like the Samsung Evos/Pros (stuff rated around 500-800TBW for a 500GB drive). So, basically, has the inclusion of ZFS in UnRaid, and it being pushed as the best thing since sliced bread (by many), led to a situation where UnRaid users may be killing their consumer SSD cache drives quicker than XFS / BTRFS cache pools? Or, is this simply a case where the combination of how Proxmox works leads to a situation where ZFS formatted drives are heavily written to? When I read pages like this, https://unraid.net/blog/zfs-guide, and when I watched Ed's tutorials, the only thing I noted was that ZFS may have more resources requirement (as in more ram usage, maybe more CPU usage) - not that it would require the purchase of more expensive drives.

 

For me, I run an 850 Pro 512GB and 860 Evo 500GB in a ZFS mirror cache pool. I have one WD Red formatted as ZFS in my array and a separate RAIDZ1 pool, with both the cache and raidz1 pool sending snapshots to the ZFS array drive. My Pro has 8.5 years power on hours (2014 purchase, lived 5 years as a Windows PC drive) and 133TB lbas written, while my Evo has 4.10 years power on hours (all as an UnRaid cache drive) with 69.8TB written. I only formatted them ZFS a couple of months ago (BTRFS, previously), so the vast majority of that usage is not from ZFS. So for me, I haven't noticed much usage with ZFS - but I hardly use my cache drives too much. My appdata/VM/ISO, etc, live on the cache drives, but the majority of write heavy processes are written directly to the array. So I'm probably not a good example.

Edited June 5 by Lebowski89

[JorgeB]

6 hours ago, Lebowski89 said:

UnRaid users may be killing their consumer SSD cache drives quicker than XFS / BTRFS cache pools?

Not really, but btrfs and zfs will usually have higher write amplification than xfs, due to being COW filesystems, especially when used with VM or database type data.