ZFS and "internal" mfi RAID cards, the eternal question

[Peter Lai]

On Fri, Jan 14, 2011 at 4:55 AM, Borja Marcos <borjam at sarenet.es> wrote:
> Hello,
>
> I've been using FreeBSD  with ZFS for some time, with varied degrees of success. Unfortunately, turns out that Dell, which is the preferred  manufacturer here, doesn't offer an appropiate configuration.
>
> They insist on selling those "RAID cards" that of course get in the way of running ZFS in the right way. With these cards you are left basicly with two options: either defining a large RAID5 logical volume and use ZFS as a file system, or define a RAID0 volume for each physical disk.

Is there a reason you are ordering your Dells with H700 instead of
H200; do you really want the battery backed cache anyway?
http://www.dell.com/content/topics/topic.aspx/global/products/pvaul/topics/en/us/raid_controller?c=us&l=en&cs=555
suggests the H200 has jbod mode...

FWIW, in our case, we didn't need 16 ports and were ok with 3gb
channels so we actually just settled with the dumb mpt controller.
> Maybe there would be a way to just tell the card firmware to shut up and let it work like a simple  and well behaved SAS card?

One could wish :)