raid1 and raid5 in one freenas for virtual servers

[silbro]

Good day

I have a mainboard with 2 sata3 ports and 4 sata2 ports. I wanted to add a raid1 with 2 * ssds (512gb) and a raidz with 4 * 7200rpm (2TB) disks. I'm using the storate for virtual servers (linux, kvm). The reason I wanted a raid 1 is because of faster I/Os for the mailserver. The rest will be 2 barely used DNS servers and storage for seafile and not that many visited webpages.

Does this make sense? Would I have an advantage with the 2 SSDs in a raid1? Any other suggestions ?

I will want to use an USB stick for the OS. Is this dangerous? What if that USB fails? Will I loose all my data? Would it make more sense to put the OS on the raid1?

Sincerely

 

[jgreco]

We do not recommend RAIDZ for VM data but as long as you're fine with performance being poor, and your application seems to be a good fit for that, there's nothing actually wrong with doing that.

The performance on a pair of mirrored SSD's will be better. Much better. Make it a separate ZFS pool, however.

FreeNAS is an appliance and does not support putting the OS on a data disk. You can put it on a USB stick, SATA DOM, or even a hardware RAID1. The USB stick is fine as long as you have a spare. Make sure to keep a copy of your configuration database offline and if there's a problem you can quickly restore service.

 

[silbro]

Thank you for you answer :) I find it very nice that freenas is so simple to use with a USB stick. I like this feature.

Is there another recommendation for my 4 disks apart from the RAIDZ configuration when using VMs?

 

[jgreco]

Two mirror vdevs. Striped. 4TB of much better storage for VM's (compared to RAIDZ).

 

[silbro]

Thank you very much for the help! Much appreciated :)