From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark delfman Subject: Re: xfs > md 50% write performance drop on .30+ kernel? Date: Tue, 13 Oct 2009 16:15:55 +0100 Message-ID: <66781b10910130815j3f8cc66al2ae03953aedb66ef@mail.gmail.com> References: <66781b10910120958k4afb637ejba79e4c23900c4da@mail.gmail.com> <20091013013352.GA24869@infradead.org> <66781b10910130406s4119985fg5db7679a2e9fd4f2@mail.gmail.com> <70ed7c3e0910130409r1e1350b6yabfdc3d4f5c51edf@mail.gmail.com> <66781b10910130412x309d9de2l574ba12a9ed4100a@mail.gmail.com> <70ed7c3e0910130415k4da86d18kd92dce5217b8600d@mail.gmail.com> <4AD48EFA.50303@shiftmail.org> <66781b10910130813u7f9ca010t7cd05214be729fff@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <66781b10910130813u7f9ca010t7cd05214be729fff@mail.gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Asdo Cc: LinuxRaid List-Id: linux-raid.ids PS - LSI havent publically released the SAS2 (non-raid) card as yet. They have just released the RAID version and will follow with the non-raid soon. Their chips are being used on some of the later server motherboards, so SAS2 is around but new. On Tue, Oct 13, 2009 at 4:13 PM, mark delfman wrote: > We dont use 10 ports, we use 8 ports > 36 port expander. The 8 ports > act as a single wide port. > > We are hitting a performance limit of circa 1.6 - 1.9GBsec regardless > of number of drives, so it max's at around 8 / 9 drives (with 15K). > RAID6 around 900MBsec i recall. =A0We expect more with emerging > expanders. > > We were hoping to use DM MPIO to increase performance using multiple > cards and paths, but MPIO at best matches performance of a single > card, most likely pulls it down.... but this is a different topic i > guess. > > XFS in the past has often increased performance - not allows on simpl= e > sequential writes, but FS's are a lot better at intelligently caching > data... so I am very keen to help in whatever way i can to resolve th= e > FS > MD performance problem. > > Thanks again.... Mark > > > On Tue, Oct 13, 2009 at 3:30 PM, Asdo wrote: >> >>> On Tue, Oct 13, 2009 at 2:12 PM, mark delfman >>> wrote: >>> >>>> >>>> We upgrading mainly because of support for the emerging LSI SAS2 c= ards >>>> (which we are beta testing now) >>>> >> >> What is this LSI SAS2 card you have with 10+ ports? The only 10+ por= ts LSI >> card I see is the 84016E and it is a SAS1. >> >> You say the driver for such card is included in the vanilla kernel a= t >> 2.6.30? That would be very nice... I grepped the 2.6.31 kernel sourc= e for >> LSI cards but I can't find device strings such as 84016E ... >> >> Thank you >> > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html