First-time production server using zfs

[rnovVcQi9Vk]

I decided to go with ZFS instead of hardware raid for a new host server for the first time. It has 4 Dell Hynix 960GB SDDs for the ZFS volume and 128GB of RAM.

The main VM is an application server that is mostly an IO-bound application with lots of smallish files as the primary database. It also runs MySQL server.

I'm hoping for some feedback, as I'm concerned about regretting either using ZFS or not using the most permanent VM hard disk setup I can.

Any feedback would be greatly appreciated.

 

[Dunuin]

Then I would try it with a striped mirror (raid10) with default ashift=12 and default volblocksize=8K. You might want to disable atime or at least enable relatime. A very low latency SSD (best would be an Intel Optane) as a SLOG might also be a good idea to increase the sync write performance for the DBs.

 

[rnovVcQi9Vk]

Thankfully that's what I did. What about the VM Hard Disk

Cache: Default (No Cache)
Discard: True
SSD Emulation: True
IO Thread: false
Read-only: Flase
Backup: True
Skip Replication: False
Async IO: Default (io_uring)

Thanks for the help

 

[Dunuin]

IO Thread: false

I would enable that, otherwise the vDisk won't get its own thread when using "virtio SCSI single" as controller.

 

[Joe Baker]

Then I would try it with a striped mirror (raid10) with default ashift=12 and default volblocksize=8K. You might want to disable atime or at least enable relatime. A very low latency SSD (best would be an Intel Optane) as a SLOG might also be a good idea to increase the sync write performance for the DBs.

I saw someone mention that on zfs the atime is somehow important for the backups. Might want to check on that advice.

 

[Dunuin]

I saw someone mention that on zfs the atime is somehow important for the backups. Might want to check on that advice.

Totally depends on the software you are running on that pool. the Proxmox Backup Server for example needs atime, so it can't be disabled. But PBS still works fine with relatime, where the access time is only updated max once every 24 hours. Without disabling atime or enabling relatime, each read operation will also cause a write operation, doubleing the IOPS.

 

[rnovVcQi9Vk]

Thanks for the followup info.