From: "mark" <dvlhntr@gmail.com>
To: "'Anthony Presley'" <anthony@resolution.com>
Cc: <pgsql-performance@postgresql.org>
References: 
 <CAO2AxyoGvmRYtq=1=weOU_CCnAxK8FboBa8GWS6XZ923CXCCgA@mail.gmail.com>
In-Reply-To: 
 <CAO2AxyoGvmRYtq=1=weOU_CCnAxK8FboBa8GWS6XZ923CXCCgA@mail.gmail.com>
Subject: Re: RAID Controller (HP P400) beat by SW-RAID?
Date: Sun, 11 Sep 2011 21:10:11 -0600
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>From: pgsql-performance-owner@postgresql.org
[mailto:pgsql-performance-owner@postgresql.org] On Behalf Of Anthony =
Presley
>Sent: Sunday, September 11, 2011 4:45 PM
>To: pgsql-performance@postgresql.org
>Subject: [PERFORM] RAID Controller (HP P400) beat by SW-RAID?

>We've currently got PG 8.4.4 running on a whitebox hardware set up, =
with
(2) 5410 Xeon's, and 16GB of RAM. =A0It's also got (4) 7200RPM SATA =
drives,
using the onboard IDE controller and ext3.=20

>A few weeks back, we purchased two refurb'd HP DL360's G5's, and were
hoping to set them up with PG 9.0.2, running replicated. =A0These =
machines
have (2) 5410 Xeon's, 36GB of RAM, (6) 10k SAS drives, and are using the =
HP
SA P400i with 512MB of BBWC. =A0PG is running on an ext4 (noatime) =
partition,
and they drives configured as RAID 1+0 (seems with this controller, I =
cannot
do JBOD). =A0I've spent a few hours going back and forth benchmarking =
the new
systems, and have set up the DWC, and the accelerator cache using =
hpacucli.
=A0I've tried accelerator caches of 25/75, 50/50, and 75/25.
>


I would start of by recommending a more current version of 9.0...like =
9.0.4
since you are building a new box. The rumor mill says 9.0.5 and 9.1.0 =
might
be out soon (days?). but that is just rumor mill. Don't bank on it.=20


What kernel are you on ?

Long time HP user here, for better and worse... so here are a few other
little things I recommend.=20

Check the bios power management. Make sure it is set where you want it.
(IIRC the G5s have this, I know G6s and G7s do). This can help with =
nasty
latency problems if the box has been idle for a while then needs to =
start
doing work.

The p400i is not a great card, compared to more modern one, but you =
should
be able to beat the old setup with what you have. Faster clocked cpu's =
more
spindles, faster RPM spindles.=20

Assuming the battery is working, with XFS or ext4 you can use nobarrier
mount option and you should see some improvement.=20


Make sure the raid card's firmware is current. I can't stress this =
enough.
HP fixed a nasty bug with Raid 1+0 a few months ago where you could eat =
your
data... They also seem to be fixing a lot of other bugs along the way as
well. So do yourself a big favor and make sure that firmware is current. =
It
might just head off headache down the road.

Also make sure you have a 8.10.? (IIRC the version number right) or =
better
version of hpacucli... there have been some fixes to that utility as =
well.
IIRC most of the fixes in this have been around recognizing newere cards
(812s and 410s) but some interface bugs have been fixed as well.   You =
may
need new packages for HP health. (I don't recall the official name, but =
new
versions if hpacucli might not play well with old versions of hp health. =


Its HP so they have a new version about every month for firmware and =
their
cli utility... that=92s HP for us.=20

Anyways that is my fast input.

Best of luck,


-Mark