FreeNAS JBOD Controller...No flash

[kjemison]

Hello,

It is my understanding that FreeNAS with ZFS prefers to have a group of hard drives as JBOD and let ZFS software RAID the drives.

I see that a lot of people running FreeNAS use IBM M1015 reflashed with IT firmware.

My question is this... Is there not any support for a JBOD controller without flashing or changing the firmware?

I just find it odd that as popular as FreeNAS is that there is no "out of the box" controller that will work.

I read through the "Recommended Hardware" for FreeNAS and even in that write up it mentions using the IBM controller with a flash to IT mode.

Just curious what others have to say.
Thank you
KJ

 

[Ericloewe]

My question is this... Is there not any support for a JBOD controller without flashing or changing the firmware?

You will always be expected to flash the firmware version that matches whatever the FreeNAS driver is at. For LSI SAS2, that's P16.

Crossflashing is a bit more complex than the average firmware upgrade, but only needs to be done once. It's also unnecessary if you straight up buy an LSI SAS 9211 or 9207. Then you only need to flash P16 IT mode, which is a simple firmware upgrade/downgrade.

 

[JDCynical]

It is my understanding that FreeNAS with ZFS prefers to have a group of hard drives as JBOD and let ZFS software RAID the drives.

I think it's more accurate to say that FreeNAS expects that it will have direct access to the drives without any abstraction layers in the way, which is what you get with a RAID card.

I just find it odd that as popular as FreeNAS is that there is no "out of the box" controller that will work.

ZFS itself was designed from the beginning to not need a hardware RAID card, and since many of them 'hide' what's happening with the drives. Look at the original 'thumper' box from Sun (x4500), it was basically nothing but drives and on-board HBA's.

JBOD mode is generally the lesser of the evils, but can sometimes cause problems, which is why IT mode is generally used, it removes the abstraction layers that would otherwise get in the way.

 

[kjemison]

Thank you for all the input! Definitely clears some things up for me.