Question regarding ProxMox / FreeNAS / ZFS RaidZ1 setup

[larathydo]

Hello,

I have a question about a project that i'm getting ready to start on. It involves having a brand new PC and using ProxMox for my virtualization needs (Primary purpose is using FreeNAS on the hardware, but I like the idea of having flexibility to setup other VMs for, let's say, a Windows Server box down the road and whatnot). And with that, my question has to do with FreeNAS. I plan on using FreeNAS 0.7.2 (I was hoping to use FreeNAS 8.2, but there were some compatibility issues for some software I want to use so I settled on 0.7.2 which should suit my needs fine) but I have a question about using it in conjunction with ProxMox. I will have a total of 5 2TB SATA hard drives that i'd like FreeNAS to take care of to create a RAIDZ1 setup.

As I understand it, one way to do it is setup 5 logical disks in ProxMox for FreeNAS to use and assign each logical disk individually to each physical HDD. However, in doing so each of FreeNAS' hard drives (from ProxMox's perspective) would be treated as a container contained on each of these separate hard disk. It would still "effectively" spread the data over the drives as I intend, but my concern is with FreeNAS not having hardware-level access to the hard drives. In other words:

a) Could it negatively impact data integrity since it's not viewing/controlling the hard drive as a whole (but merely controlling a container file on the HDD) in the event of physical issues with the disk?
b) Would it adversely effect FreeNAS' ability to use S.M.A.R.T monitoring of the HDDs to preemptively warn of / look for issues?

Just curious if anyone has setup a FreeNAS box through ProxMox and/or could comment on the above concerns I have with that kinda setup. The only thing i've found that might work (unless my above concerns are unfounded) is the following:

http://pve.proxmox.com/wiki/FAQ#How_can_I_assign_a_physical_disk_to_a_VM.3F

How can I assign a physical disk to a VM?

You don't have to do anything at host level (i.e. not add to fstab or anything), just set is as available directly to the KVM guest:

qm set <vmid> -ide# /dev/sdbOr:

qm set <vmid> -ide# /dev/disk/by-id/[your disk ID]...since having the drive letter change (should you add a drive) might have unintended consequences.
Also see /etc/qemu-server/<vmid>.conf if you want to add it editing the conf file by hand (i.e. adding ide1: /dev/sdb2). After that you can run the VM as usual, and you will have the new storage device available inside it. Beware that you can't assign it to more than one running VM if the filesystem is not designed for such scenario.

Would the above suggestion work or is it not worth the trouble / no issues would arrise using the usual container method.

Thanks in advance for any help!

 

[taspenatu]

Theoretical you can install Proxmox to one disk and assign the remaining 4 physical disks directly to the FreeNAS VM.

Or create 4 LVM volume groups each with a single disk and provide them as storage to Proxmox.
Then create one virtual disk on each storage and assign it to your FreeNAS virtual machine.
This gives you the possibility of snapshot backups.

But what if the Proxmox system disk fails...

The result will probably be that you end up in a software raid configuration which is not supported by Proxmox.

I'd suggest to use a hardware raid controller and assign a virtual disk with raw format and nocache option to the FreeNAS VM.