# A good SAS card for ZFS



## stevekez (Jul 26, 2010)

Hi everyone,

I've been doing lots of research into SAS HBAs that are compatible with FreeBSD but still need some assistance in making the right choice, if anyone can help me.

I'm putting together a spec for a 24-drive system that'll hopefully be using a Supermicro chassis with SAS backplane containing expander, so all I need is a single mini-SAS connection to a 4-port controller. Failing that, the alternative chassis I'm looking at has no expanders, instead offering a 20-disk enclosure via five 4-port mini-SAS connections.

Disk bandwidth isn't too big an issue as at best it'll be networked via a pair of trunked Gigabit NICs. I want to make use of ZFS's snapshot features and deduping; it's going to be a backup NAS.

So my question is, what SAS PCIe controllers are out there that are either plain HBAs or RAID controllers that provide passthrough for direct access to the disks (or support single-disk access, preferably without needing to write metadata to the disks)?

PCIe preferred over PCI, although I guess PCI-X might be possible.

If I've left out any key information, feel free to slap me.

Thanks for your help.
Steve.


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## Matty (Jul 27, 2010)

You don't get deduping with FreeBSD right now.


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## fronclynne (Jul 27, 2010)

Dedupe should be in soon enough, though.

The only SAS-specific controller with passthrough that I can find is mfi(4) (the passthrough is "device mfip"(no manpage, also not listed in mfi(4))).

I dunno if other, perhaps better controllers are supported by legacy drivers.  I'm kind of blindly stabbing here, but ahc(4) comes to mind as a fairly solid SCSI driver.  The old server stuff I used to play with would sometimes have an on-board sym(4) controller, probably no SAS stuff uses that chip, though.


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## Matty (Jul 27, 2010)

fronclynne said:
			
		

> Dedupe should be in soon enough, though.



soon as in over a year or more.


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## User23 (Jul 27, 2010)

I use this ... with FreeBSD + ZFS as a NFS server.

http://www.lsi.com/channel/products/raid_controllers/sata_sas/3ware_9690sa8i/index.html
http://www.supermicro.com/products/chassis/4U/846/SC846E2-R900.cfm

It has a redundant backplane with dual LSI SASX36 expander chips.

Here is a link to harddrive, motherboard and chassis compatibility list for 3ware Controllers: http://www.3ware.com/products/sys_compatibility.asp

I never had a mainboard that wont work with the 3ware Controllers, but check the drive and chassis(backplane) compatibility should be necessary.


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