Help with RAID setup

[nerdtron]

Hi all,

I have an LSI MegaRAID controller and 12 HDDs that I want to setup for RAID 6.
I'm not familiar on how to group the drives, is it 4 volume groups with 3 HDD each, or 3 volume groups with 4 HDD each? Not to mention 2x6 or 6x2 combinations. Or just one big volume group?

I'm familiar with RAID 10 setups, I configure it with 2 volume groups and 6 drives each. But how do I group the drives for RAID 6?

Thanks!

[CharlesA]

Are you wanting to do one big RAID6 array or smaller RAID6 arrays?

If you are going to use it like one huge disk, just add the drives to the array and you'll be good to go. The OS should see it as xx TB in size.

[nerdtron]

That's what I'm not sure about, is it better to use one large disk or smaller arrays? We are going to use it for File Storage with NAS4Free as the OS.

Will smaller arrays still work if two drives fail?

[CharlesA]

I dunno. I've always done one huge array. With RAID6, you'll be protected from 2 drive failures, so I'd go with a 12 disk RAID 6 array and see what happens.

[nerdtron]

Alright then, I'll go with one large array. Thanks

[CharlesA]

Welcome.

Let me know how you go about creating it cuz I'm going to be migrating my current RAID card to MegaRAID and have no idea what I'm doing.

[rubylaser]

NAS4Free's default filesystem is ZFS. With ZFS, hardware RAID controllers are about the last thing you want to use. It prevents ZFS from giving you almost all of it's good benefits. All you really need is a "dumb" HBA like the IBM m1015 or LSI 9211-8i in IT mode to hang your disks off of. For a simple fileserver, I would suggest one large RAID6 array (or raidz2 in ZFS speak).

[rubylaser]

Welcome.

Let me know how you go about creating it cuz I'm going to be migrating my current RAID card to MegaRAID and have no idea what I'm doing.

I know someone you could ask if you have any questions

[CharlesA]

NAS4Free's default filesystem is ZFS. With ZFS, hardware RAID controllers are about the last thing you want to use. It prevents ZFS from giving you almost all of it's good benefits. All you really need is a "dumb" HBA like the IBM m1015 or LSI 9211-8i in IT mode to hang your disks off of. For a simple fileserver, I would suggest one large RAID6 array (or raidz2 in ZFS speak).

I had no idea a file system would negate the benefit of using a hardware RAID card. *goes off to google*

I know someone you could ask if you have any questions

Lol. This is true.

[rubylaser]

I had no idea a file system would negate the benefit of using a hardware RAID card. *goes off to google*

The filesystem doesn't negate the benefit of hardware RAID. In the case of ZFS, the hardware RAID card prevents some ZFS's features from working. Here are a few from Wikipedia.