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Date:      Mon, 1 Aug 2016 08:45:04 +0200
From:      "O. Hartmann" <ohartman@zedat.fu-berlin.de>
To:        Borja Marcos <borjam@sarenet.es>
Cc:        Jason Zhang <jasonzhang@cyphytech.com>, freebsd-performance@freebsd.org, freebsd-current@freebsd.org, freebsd-hardware@freebsd.org, freebsd-stable@freebsd.org
Subject:   Re: mfi driver performance too bad on LSI MegaRAID SAS 9260-8i
Message-ID:  <20160801084504.563c79cf@freyja.zeit4.iv.bundesimmobilien.de>
In-Reply-To: <B2239257-E136-4918-8FA3-1EE51BC50FB4@sarenet.es>
References:  <16CD100A-3BD0-47BA-A91E-F445E5DF6DBC@cyphytech.com> <1466527001.2694442.644278905.18E236CD@webmail.messagingengine.com> <1790833A-9292-4A46-B43C-BF41C7C801BE@cyphytech.com> <B2239257-E136-4918-8FA3-1EE51BC50FB4@sarenet.es>

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On Wed, 22 Jun 2016 08:58:08 +0200
Borja Marcos <borjam@sarenet.es> wrote:

> > 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 GE=
OM 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. =20
>=20
> 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
>=20
> Add this to /boot/loader.conf
>=20
> hw.mfi.allow_cam_disk_passthrough=3D1
> mfip_load=3D=E2=80=9CYES"
>=20
> And do the tests accessing the disks as =E2=80=9Cda=E2=80=9D. To avoid co=
nfusions, 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.
>=20
>=20
>=20
>=20
> Borja.
[...]

How is this supposed to work when ALL disks (including boot device) are set=
tled
with the mfi (in our case, it is a Fujitsu CP400i, based upon LSI3008 and
detected within FreeBSD 11-BETA and 12-CURRENT) controller itself?

I did not find any solution to force the CP400i into a mode making itself
acting as a HBA (we intend to use all drives with ZFS and let FreeBSD
kernel/ZFS control everything).

The boot device is a 256 GB Samsung SSD for enterprise use and putting the =
UEFI
load onto a EFI partition from 11-CURRENT-ALPHA4 is worse: dd takes up to
almost a minute to put the image onto the SSD. The SSD active LED is blinki=
ng
alle the time indicating activity. Caches are off. I tried to enable the ca=
che
via the mfiutil command by 'mfiutil cache mfid0 enable', but it failed ... =
It
failed also on all other attached drives.

I didn't further go into more investigations right now, since the experience
with the EFI boot loader makes me suspect bad performance and that is harsh=
 so
to speak. Glad to have found this thread anyway.

I cross post this also to CURRENT as it might be an issue with CURRENT ...

Kind regards,

Oliver Hartmann



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