Hardware raid or ZFS?

[Alessandro 123]

I have to evaluate performance between an hardware raid6 or a zfs raiz2.
If hw raid is faster, i'll go with that.
I've already defined the fault tolerance criteria: i need a raid6 as I have on all of my servers.

 

[kobuki]

But ZFS is not just about speed, it's a lot of added functionality you will never have with any HWRAID card. Defining a single criteria like speed makes no sense in my eyes. After judging that HWRAID is faster on your own system by 5% in synthetic tests, does that clearly indicate you'll benefit from that and decide you need to use that? I could only echo what @alexskysilk said in his post. Of course there are situations where pure speed is everything, but we don't really know from what you told us (pretty much nothing).

 

[Alessandro 123]

It depends on speed difference. Only 5% ? Ok, i can go with ZFS.
hwraid is twice faster? I have no choise, hwraid is the solution for me.

It depends.

 

[kobuki]

What do you need speed for? Can we have a glimplse of your planned setup? It won't be a double in speed difference but IOW will be much higher. Is that even important for you?

 

[Alessandro 123]

This node will host about 45 VMs, some of them (at least 2 or 3) with very intensive I/O.
It will replace a similiar node, same hardware, same VM and I can't put anything slower than now. This is why I would like to double check the performance, as currently I'm using a RAID-6 hardware on a XenServer and I have to replace everything with proxmox on an identical hardware

 

[kobuki]

I see. With a single-vdev raidz2 speed would be slow for writing generally since it would be as slow as a single component disk. ZFS really shines with many vdevs, so eg. with multiple raidz2 vdevs striped, and possibly cache device(s) added. I think it would be a fair comparison then. Otherwise you might find you really don't benefit from it.