Proxmox install not recognizing mirror drives as the same

[pcie]

Hi,

I am trying to install Proxmox 3.4 for our corporate server. I have two SATA hard drives installed - both WDC WD7501AALS-0 at 698GB.

The Installation recognizes both disks as /sda and /sdb, but when I try to install Proxmox as a ZFS RAID1, I get an error message:

Warning: mirrored disks must have the same size
Please fix ZFS setup first.

...and I can't proceed. How can I get this to work?

Thanks,

-PC

 

[RobFantini]

I'd try wiping existing partition table before install. Sometimes I've had to do so depending on how the drives were used prior.

 

[pcie]

I took the drives to another system and erased the partition tables. It didn't help.

The system is a Supermicro 2022G-URF4+ with it's native adaptec controller, and the drives are both WDC WD7501AALS-0.

I'm providing this information for others, as we have decided to go with RAID 1 on the Adaptec, and then I'll probably run a standard ZFS FS on top of that..

Thanks for your help.

-PC

 

[mir]

Running ZFS on-top hardware raid is a very bad choice. It more or less nullifies the benefits of ZFS.

 

[pcie]

Yeah, that's what I've heard, but I've also been hearing conflicting reports. All of our storage systems have hardware striping at the least. On top of that I was considering running ZFS mirroring to create 0+1 block devices, and on top of that my KVM machines, which I plan to install with ZFS as well (using the aforementioned block devices).. The main reason I want to use ZFS is for the snapshots, since they are much more efficient than lvm snapshots for file-level backups of my host OS and/or VMs. The other benefits of ZFS are secondary

I would like to hear comments on my potential setup, since I'd rather spit the RAID 0 and RAID 1 if I can. I'm not even sure if ZFS can do RAID 0+1, though I suspect it can.

Anyway, the proxmox install still doesn't recognize my drives as RAID-1-capable so I don't have much choice. either way.

-PC

 

[RobFantini]

Why not get a LSI or Supermicro sata card and use in IT mode? If you are not are not familiar with those search around. I had my son get a couple and flash for a couple of our systems. lspci shows the card as:Serial Attached SCSI controller: LSI Logic / Symbios Logic SAS2008 PCI-Express Fusion-MPT SAS-2 [Falcon] (rev 03)

you could probably get a used card fairly cheap. you've got the right idea to use zfs. I'd get a card that works better with zfs.

 

[pcie]

Thanks for your response, I really appreciate it.

Regarding the main array, we already bought dual Areca ARC-1882 SAS cards with BBU.

At first my intent was to offload the RAID-0 burden onto hardware RAID, and then use ZFS to RAID-1. However, I'm also strongly considering ZFS-only RAID10 with the controllers put in pass-through mode, which it seems is their equivalent of "IT" mode. I've been reading some people say there is little performance benefit in letting the controller do half the RAID, but I don't know enough about ZFS to know for sure. If anyone else has this setup, I'd love to hear any comments.


In terms of the original problem though, the native SATA card is just for the boot drives which I was trying to ZFS mirror. I will resort to using the on-board RAID, but it does seem that there is an install issue here that people should know about.

-PC

 

[pirateghost]

When it comes to zfs, you should never let hardware raid get between zfs and the disks. Letting zfs control "half" of your raid config makes no sense. Zfs needs direct access to hardware (disks) in order to be beneficial and operate in a proper manner

 

[pcie]

Right. I'll use All-ZFS RAID-10.

This may be a new thread, but I'm curious if ZFS running in the guest in this case, would be able to reach the drives directly through the the Host ZFS RAID 10.