Is it safe to disable checksum on nested zfs?

[kskb]

Hi, I'm currently installing truenas scale in proxmox, and my PVE installed with a zfs raidz pool which is not possiable to change at this time.

But truenas uses zfs as the filesystem, which is not a good idea because this is zfs on zfs, it doing checksum twice!

Is it safe to disable checksum in truenas?

 

[Ericloewe]

It should be fine, but really, that is so far down the list of things to worry about... Doing two sets of fletcher checksums for the boot pool is going to have basically zero impact.

 

[kskb]

Not only the boot pool, but also the TrueNAS data pool is a virtual disk in a RaidZ pool on PVE.

 

[Ericloewe]

OK, that makes zero sense for many of the reasons that Hardware RAID makes zero sense.

The only correct way of running TrueNAS in a VM is to pass through a suitable HBA and have TrueNAS access the disks like it would on bare metal.

Disabling checksum would not solve any of your problems and might actually make things worse.