Hello,
I just installed TrueNAS Core 13 (which I couldn’t have done without advice in other threads here–thanks again!).
Unlike Proxmox, the installer didn’t give me an option to set the ashift value for the boot NVME.
When I ask ZFS what the ashift value is via zpool get ashift
, I get this:
# zpool get ashift
NAME PROPERTY VALUE SOURCE
SSD-Pool ashift 12 local
boot-pool ashift 0 default
After some research, my understanding is that a value of 0 is “auto-detected,” which means it asks the drive.
I want to make sure it didn’t assign the NVME an ashift of 9.
I did some googling and got halfway there.
Running zdb -S -U /data/zfs/zpool.cache
and then zdb -U /data/zfs/zpool.cache | grep ashift
gets me the ashift for the SSD-Pool, but I can’t figure out how to do the same thing for the boot pool.
I know that ZFS stores the boot pool cache, when it exists, at /etc/zfs/zpool.cache
, so I thought maybe I could just run the command zdb -S -U /etc/zfs/zpool.cache
, but I don’t entirely understand what that does and I’m wary of poking at the boot pool too much (compared to an empty data pool I haven’t started using yet).
What’s the easiest way to get the actual ashift for the boot pool? Am I worried over nothing? I’d think in 2024 TrueNAS Core would be set up to avoid write amplification on the boot SSD, but I wanted to make sure.
Thanks!