Date: Fri, 18 Jan 2013 16:58:47 -0500 From: Karim Fodil-Lemelin <fodillemlinkarim@gmail.com> To: Mark Felder <feld@feld.me> Cc: freebsd-hackers@freebsd.org Subject: Re: IBM blade server abysmal disk write performances Message-ID: <50F9C597.7010608@gmail.com> In-Reply-To: <op.wq34qcdk34t2sn@markf.office.supranet.net> References: <CAA3ZYrB%2B4LU=YRQsvYB19sE9ywjejyP7Gc4j8fpTGx2LaZm4kw@mail.gmail.com> <50F87741.4030201@gmail.com> <op.wq34qcdk34t2sn@markf.office.supranet.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On 18/01/2013 10:16 AM, Mark Felder wrote: > On Thu, 17 Jan 2013 16:12:17 -0600, Karim Fodil-Lemelin > <fodillemlinkarim@gmail.com> wrote: > >> "SAS controllers may connect to SATA devices, either directly >> connected using native SATA protocol or through SAS expanders using >> SATA Tunneled Protocol (STP)." >> The systems is currently put in place using SATA instead of SAS >> although its using the same interface and backplane connectors and >> the drives (SATA) show as da0 in BSD _but_ with the SATA drive we get >> *much* better performances. I am thinking that something fancy in >> that SAS drive is not being handled correctly by the FreeBSD driver. >> I am planning to revisit the SAS drive issue at a later point >> (sometimes next week). > > Your SATA drives are connected directly not with an interposer such as > the LSISS9252, correct? If so, this might be the cause of your > problems. Mixing SAS and SATA drives is known to cause serious > performance issues for almost every > JBOD/controller/expander/what-have-you. Change your configuration so > there is only one protocol being spoken on the bus (SAS) by putting > your SATA drives behind interposers which translate SAS to SATA just > before the disk. This will solve many problems. Not sure what you mean by this but isn't the mpt detecting an interposer in this line: mpt0: <LSILogic SAS/SATA Adapter> port 0x1000-0x10ff mem 0x99910000-0x99913fff,0x99900000-0x9990ffff irq 28 at device 0.0 on pci11 mpt0: MPI Version=1.5.20.0 mpt0: Capabilities: ( RAID-0 RAID-1E RAID-1 ) mpt0: 0 Active Volumes (2 Max) mpt0: 0 Hidden Drive Members (14 Max) Also please not SATA speed in that same hardware setup works just fine. In any case I will have a look. Thanks, Karim.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?50F9C597.7010608>