Date: Wed, 22 Jun 2016 08:58:08 +0200 From: Borja Marcos <borjam@sarenet.es> To: Jason Zhang <jasonzhang@cyphytech.com> Cc: Mark Felder <feld@FreeBSD.org>, freebsd-performance@freebsd.org, freebsd-stable@freebsd.org, freebsd-hardware@freebsd.org Subject: Re: mfi driver performance too bad on LSI MegaRAID SAS 9260-8i Message-ID: <B2239257-E136-4918-8FA3-1EE51BC50FB4@sarenet.es> In-Reply-To: <1790833A-9292-4A46-B43C-BF41C7C801BE@cyphytech.com> References: <16CD100A-3BD0-47BA-A91E-F445E5DF6DBC@cyphytech.com> <1466527001.2694442.644278905.18E236CD@webmail.messagingengine.com> <1790833A-9292-4A46-B43C-BF41C7C801BE@cyphytech.com>
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> On 22 Jun 2016, at 04:08, Jason Zhang <jasonzhang@cyphytech.com> = wrote: >=20 > Mark, >=20 > Thanks >=20 > We have same RAID setting both on FreeBSD and CentOS including cache = setting. In FreeBSD, I enabled the write cache but the performance is = the same. =20 >=20 > We don=E2=80=99t use ZFS or UFS, and test the performance on the RAW = GEOM disk =E2=80=9Cmfidx=E2=80=9D exported by mfi driver. We observed = the =E2=80=9Cgstat=E2=80=9D result and found that the write latency > is too high. When we =E2=80=9Cdd" the disk with 8k, it is lower than = 1ms, but it is 6ms on 64kb write. It seems that each single write = operation is very slow. But I don=E2=80=99t know > whether it is a driver problem or not. There is an option you can use (I do it all the time!) to make the card = behave as a plain HBA so that the disks are handled by the =E2=80=9Cda=E2=80= =9D driver.=20 Add this to /boot/loader.conf hw.mfi.allow_cam_disk_passthrough=3D1 mfip_load=3D=E2=80=9CYES" And do the tests accessing the disks as =E2=80=9Cda=E2=80=9D. To avoid = confusions, it=E2=80=99s better to make sure the disks are not part of a = =E2=80=9Cjbod=E2=80=9D or logical volume configuration. Borja.
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