Dell branded storage controller for ZFS file-server | Advice requested

[David Gwynne]

> On 23 Jan 2015, at 7:16 pm, Ahmed Kamal <email.ahmedkamal at googlemail.com> wrote:
> 
> Hi everyone,
> 
> I'm looking to build a ZFS file-server, unfortunately I'm locked into Dell
> branded hardware only. I know Dell sometimes ships LSI branded cards, but
> that too probably won't work for me, as I live outside the US and the local
> Dell rep is clueless (so whatever I want to buy, has to be on Dell's
> website). I am considering Dell R720xd or R730xd. I will use Intel i350
> NICs, and ECC RAM, but the biggest questions are around the SAS HBA
> 
> Per my research, I have the following notes and questions. Appreciating
> your comments on them
> 
> * H310 Card supports syspd (jbod) mode per
> http://svnweb.freebsd.org/base?view=revision&revision=254906 so it is
> probably the best card for what I want to do, right?

no.

> * H310 is a low end card, it has very limited queue depth (25 I believe) ..
> Is this actually a problem when using the disks (20 x SAS 10k disks) in
> syspd/jbod mode? what about if I attach a couple of SSD disks?

there are two queue limits here, one for the controller and one for each disk attached to it.

h310s have a controller queue depth of 31, ie, they can only support 31 commands at a time. if you have 24 disks and distribute the controllers command slots between them, thats about 1 command per disk.

> * H310 can be flashed to IT mode (LSI firmware), and is supported by
> Illumos kernel (if I'll ever need that) .. so overall it looks like a good
> option. Any "watch-outs" I should be aware of ?

yes. if you flash the h310 to become an sas hba, the pci product/vendor and subproduct/subvendor ids on the controller change. the dell bios will refuse to boot if it detects an unsupported controller in its storage slot. you'll brick the machine until you remove the h310. because it is on a non standard mezzanine connector you will not be able to flash it back to a h310, and you'll have a useless chunk of silicon to put on your desk as a monument to how annoying vendors are.

> * H710/p have no way of exposing JBOD/syspd in any way .. If using those
> cards, the best I can do, is to create a raid-0 per disk, and put zfs on
> top of that. How bad is this? Is the only problem that I'm locked into H710
> firmware? Would the nvram and bbu on H710 improve performance significantly
> vs H310?

i wouldnt run zfs on that.

> * H330 and H730, seem supported by mrsas driver. Is this driver able to
> expose jbod/syspd mode? If yes, what's the overall advise, should I go with
> one of those, or the "trusty" H310 ?

thats a workable option. h330 should be fine if all you want to do is jbod.

> 
> Your help and advice is most appreciated
> _______________________________________________
> freebsd-scsi at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-scsi
> To unsubscribe, send any mail to "freebsd-scsi-unsubscribe at freebsd.org"