Date: Mon, 2 Mar 2009 13:52:16 -0600 From: Josh Paetzel <josh@tcbug.org> To: Scott Long <scottl@samsco.org> Cc: freebsd-scsi@freebsd.org Subject: Re: twa driver and 3ware 9690SA issues Message-ID: <49E31E02-E9B0-48EB-8B7A-0517C6501FC2@tcbug.org> In-Reply-To: <49AC370A.1040700@samsco.org> References: <09CE3D22-431A-433F-9CAF-6896FF77DDB1@tcbug.org> <49AC370A.1040700@samsco.org>
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On Mar 2, 2009, at 1:44 PM, Scott Long wrote: > Josh Paetzel wrote: >> This is somewhat of a repost from questions@, and I'm currently >> engaged with 3ware about this issue. >> I have several 3ware 9690SA SAS RAID controllers. This item is >> very similar to their 9650SE controller. It uses the same firmware >> and driver, the difference being it can handle SAS drives. Up >> until this point all of the arrays we've used with these drives >> have been RAID 1 arrays with 7200 RPM SATA drives, but recently >> we've started using 15,000 MBA series Fujitsu SAS drives in places. >> The arrays have always been detected as: >> da0: <AMCC 9690SA-4I DISK 4.06> Fixed Direct Access SCSI-5 device >> da0: 100.000MB/s transfers > > This 100.000MB/s number is fictitious. The driver is just filling > in a > dummy value. Filling in the real number would require the driver > being > able to query the card for the negotiated bus speed. I have no idea > if that's possible for TWA given the programming information that is > public for the card. > >> Which wasn't that much of an issue, as SATA drives aren't capable >> of sustained sequential 100 MB/sec transfers anyways, but the SAS >> drives we are getting are supposedly capable of 180 Megs/sec and >> I'm not seeing it. I'm unsure of how to eliminate caching from the >> equation, simple tests like dd if=/dev/zero of=testfile bs=8m >> count=1000 seem to support what dmesg reports by returning 96 Meg/ >> sec transfer rates > > FreeBSD limits individual I/O segments through the CAM subsystem to > 64K. It can safely be raised to 128K via some patches that I have, > and > you will see a corresponding improvement in performance. I don't > believe that it can be safely raised above that for the TWA > controllers. > > Scott I'd like to try the patches. Where can I get them from? Thanks, Josh Paetzel
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