Attaching a DAS to a FreeNAS server

[James Richardson]

Hello again guys,

Just had a wondering about DAS devices, the server attached to our DAS is Windows server at the moment, I had to install software and drivers before it will pick it up properly.

How would I go about attaching and running the DAS on a FreeNAS server running 9.10, maybe thinking about moving the DAS to a FreeNAS server or rebuild the Windows server and make it into a FreeNAS instead?

Thanks
James

 

[danb35]

How would I go about attaching and running the DAS on a FreeNAS server running 9.10

You wouldn't, pretty much. Unless it presents itself as a block device over an interface supported by FreeBSD 10 (e.g., SAS or USB), and you're going to use it as a simple attached block device, and you're going to format it with ZFS, it's not going to happen.

 

[James Richardson]

Well it's SAS connection not USB, so is that a flat out NO haha?

I've a got another one DAS device and have it attached to the FreeNAS server from the get go, i will work if i upgrade to 10 and it presents itself as a block device?

Thanks
James

 

[danb35]

No, a SAS connection should work (and be much better than USB, really). But what are we dealing with, here? Is it just a SAS drive shelf? If so, making that work should be trivial. Or does the "DAS" do some management of its own?

 

[James Richardson]

Okey dokey cool it's a Dell poweredge MD3200, i've got it attached on 2 servers at the moment and there setup in a failover cluster.

There is a some management software to install, so i can setup LUN's, storage size, etc, it also installs drivers as well. I've attached a screenshot.

Thanks
James

 

[Arwen]

That does appear to be a hardware RAID device. In general, they are not suitable for use with ZFS, since ZFS wants to perform its own software based RAIDing. Basically without raw disks presented to ZFS, you loose some recoverability. And if you present a hardware RAID-5/6 as a LUN to ZFS, ZFS can only detect problems, not fix them.

One thing ZFS was designed to do, was use the computer's main CPU and memory for its software RAID. This is because the computer's main CPU is generally MUCH faster than a hardware RAID controller, (even with application specific hardware assists). Plus, the main computer's RAM is generally much larger than a hardware RAID controller's cache RAM.

 

[danb35]

I'm not at all familiar with that unit--is it possible to simply present the individual disks to the attached computer? If so, it could work safely, though it's still probably not optimal.

 

[gpsguy]

btw, FreeNAS 10 aka Corral is dead. See - https://forums.freenas.org/index.php?threads/important-announcement-regarding-freenas-corral.53502/

if i upgrade to 10

 

[Stux]

Is this dell device actually a SAN, presenting iSCSI to FreeNAS.