Hardware RAID - to use or ignore?

[jimjamz]

I've read conflicting arguments on whether to use and how to use hardware RAID controllers with FreeNAS? Is there any point, purpose or benefit to this?

I have an old ASROCK motherboard with an nForce3 250 Chipset that has an onboard SATA-II JMicron JMB363 (PCIE x1 interface), support RAID (RAID 0, RAID 1 and JBOD), NCQ, AHCI and Hot Plugging.
This is enabled in the BIOS but none of the drives are in any type of RAID configuration at present.

I've read in the FreeNAS documentation that this controller is supported, but supported for what purpose? Can I get any use out of this controller in use with FreeNAS, or am I best disabling it and relying on FreeNAS software control?

 

[joeschmuck]

FreeNAS needs to use a software RAID and it's own, never a hardware RAID controller. Can't be any clearer than that. If you must use this card, disable the RAID features.

 

[BigDave]

Best practices for FreeNAS (current stable version) is for the OS to have direct
access to the drives.
So for a JMB36x controller, AHCI mode would be what Joe is recommending.

 

[Ericloewe]

I've read conflicting arguments on whether to use and how to use hardware RAID controllers with FreeNAS?

Where did you read that?

nForce3 250 Chipset

Oh god...

SATA-II JMicron JMB363

Ouch.

 

[BigDave]

^^^^^^^^^^^^^^^^^^
rotflol

 

[jgreco]

Where did you read that?

Probably one of the same places all the PSU misinformation comes from.

 

[Ericloewe]

Probably one of the same places all the PSU misinformation comes from.

I can understand the PSU bullshit, since there's a large (by comparison) PC builder market where any two-bit idiot can get exposure.

However, this isn't the first time someone shows up and specifically says that the use of HW RAID controllers with ZFS is a matter subject to debate. To me, this sounds like there's a specific place where a woefully unbalanced and uninformed discussion took place. If there's one thing I don't like, it's sources of bullshit. For every source of bullshit, we need a sink to keep it from spreading to infinity.

And I can't believe I just modeled the flow of bullshit information as potential flow...

 

[jimjamz]

@joeschmuck - Thanks! That's all I needed to hear. This was my feeling all along. I'll make sure the JMicron controller can keep the drives active but there are no RAID features enabled.

To the others - rest assured, having read articles about using HW RAID with FreeNAS, my first reponse was, "Why?". I don't see the purpose of it myself, but I think it was aimed at explaining other "potential" features of FreeNAS where a HW RAID might have been beneficial. Frankly, these claims have not been backed up and I'm happy to know that I was on the right track before even reading that stuff. No, I won't post any links as I don't want to start anything. That's the Internet - we have to accept there will always be BS and contradictory terms out there. Let it go, ignore it and move on.

Oh, and don't knock the hardware. This machine has been kicking around for years without a purpose. I thought, what better way to put it to some use of backing up a few files to some redundant drives, and at the same time, getting some hands-on practical time in with FreeNAS over a weekend. It's all good learning.

 

[SweetAndLow]

but I think it was aimed at explaining other "potential" features of FreeNAS where a HW RAID might have been beneficial.

There are zero reasons to ever run hardware raid with zfs. This information is just wrong and should be corrected because if people follow that advice they will lose their data.

 

[jgreco]

There are zero reasons to ever run hardware raid with zfs. This information is just wrong and should be corrected because if people follow that advice they will lose their data.

Not QUITE true but the exceptions to the rule already know with 100% certainty why they're able to make an exception... for anyone who isn't a FreeBSD+ZFS guru and hardware wizard, @SweetAndLow is correct.