Best way to setup my pool on TrueNAS Scale

[bluepr0]

Hello everyone,

Been using TrueNAS for a few years now and when I "upgraded" to Scale from Core I started reading some documents about ZFS that made me realize that my pool is very badly set up and at high risk of losing data.

What I have now

Code:

root@truenas[~]# zpool status
  pool: boot-pool
 state: ONLINE
status: Some supported and requested features are not enabled on the pool.
    The pool can still be used, but some features are unavailable.
action: Enable all features using 'zpool upgrade'. Once this is done,
    the pool may no longer be accessible by software that does not support
    the features. See zpool-features(7) for details.
config:

    NAME        STATE     READ WRITE CKSUM
    boot-pool   ONLINE       0     0     0
      sdf3      ONLINE       0     0     0

errors: No known data errors

  pool: main
 state: ONLINE
  scan: resilvered 4.97G in 00:00:27 with 0 errors on Tue Nov 22 21:35:29 2022
config:

    NAME                                      STATE     READ WRITE CKSUM
    main                                      ONLINE       0     0     0
      raidz1-0                                ONLINE       0     0     0
        7f89c440-6af0-11ec-9fe8-4139f90800fa  ONLINE       0     0     0
        00809f86-75f5-11ec-b9ac-c159f949a17d  ONLINE       0     0     0
        7fbd9a72-6af0-11ec-9fe8-4139f90800fa  ONLINE       0     0     0
    special
      mirror-2                                ONLINE       0     0     0
        fa4856c1-6d77-11ec-bb14-ef46e90fd7e9  ONLINE       0     0     0
        f966157c-85f0-417e-9f54-80a81f71ebb1  ONLINE       0     0     0

errors: No known data errors

Main pool RAIDZ1
3x 4TB HDD (2 Seagate and 1 WD RED NAS)
- Model Number: ST4000VN008-2DR166
- Model Number: ST4000VN008-2DR166
- Model Number: WDC WD40EFRX-68WT0N0

Special VDEV (this is not even used looking at reporting)
2x 250GB SSD
- Model Number: Samsung SSD 850 EVO 250GB

Host configuration
- Running Proxmox on Intel(R) Core(TM) i7-6700T CPU @ 2.80GHz with 46GB of RAM in total
- TrueNAS running on a VM with 8 cores and 32GB of RAM
- The main usage of TrueNAS is as storage (Backups from macOS, Nextcloud data /NFS share, immich data /NFS share, etc) and to keep data safe (LOL), all my services are running outside in other dockers/VMs

After reading (and barely understanding half of it) these documents:
- https://www.truenas.com/community/threads/the-path-to-success-for-block-storage.81165/
- https://www.truenas.com/community/threads/some-insights-into-slog-zil-with-zfs-on-freenas.13633/
- https://www.truenas.com/community/threads/slog-benchmarking-and-finding-the-best-slog.63521/

I'm trying to re-build my ZFS pool in a better way, where it not only performs better (if possible) but also makes a better use of the cache – this last bit looks like with my amount of RAM is not going to happen.

Anyway, this is what I've come up with, which is probably bad but just wanted to get your opinion and help me shape it in a quicker and safer pool

Main pool
2x 4TB Seagate ZRAID1 (*WD HDD is out of the pool, either not using it or as a replacement – this is pretty old disk already)

Cache
- On this one I'm a bit lost on how I can do the best use of my 2x256GB SSD. These SSDs are also quite old so I wouldn't trust it for keeping data, just to speed up the overall functionality of the server

Questions
1. What do you think about the new main pool configuration? Should I still use the WD disk somehow?
2. What would be the best use of those SSDs, if any?
3. What would be the best way to measure the current performance of the pool to compare it later when I rebuild it?

Thanks!

 

[bluepr0]

Hey!
I wanted to do a follow-up on my NAS. I created a pool using the 2x4TB Seagate drives (which are identical models and quite new).

As for the Cache, none of the VDEV types I tried seemed to use enough of them so I ended up creating an SSD pool where I'm storing some data I usually access every day, this data is also backed up hourly to Backblaze.