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Date: Tue, 2 Mar 2010 20:26:58 -0700
Message-ID: <dcc563d11003021926l16daf2a3t78869a6a9a53271a@mail.gmail.com>
Subject: Re: 10K vs 15k rpm for analytics
From: Scott Marlowe <scott.marlowe@gmail.com>
To: Francisco Reyes <lists@stringsutils.com>
Cc: Greg Smith <greg@2ndquadrant.com>, Yeb Havinga <yebhavinga@gmail.com>,
	Pgsql performance <pgsql-performance@postgresql.org>
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On Tue, Mar 2, 2010 at 7:44 PM, Francisco Reyes <lists@stringsutils.com> wr=
ote:
> Greg Smith writes:
>
>> http://www.3ware.com/KB/Article.aspx?id=3D15383 =A0I consider them still=
 a
>> useful vendor for SATA controllers, but would never buy a SAS solution f=
rom
>> them again until this is resolved.
>
>
> Who are you using for SAS?
> One thing I like about 3ware is their management utility works under both
> FreeBSD and Linux well.

The non-open source nature of the command line tool for Areca makes me
avoid their older cards.  The 1680 has it's own ethernet wtih a web
interface with snmp that is independent of the OS.  This means that
with something like a hung / panicked kernel, you can still check out
the RAID array and check rebuild status and other stuff.  We get a
hang about every 180 to 460 days with them where the raid driver in
linux hangs with the array going off-line.  It's still there to the
web interface on its own NIC.  Newer kernels seem to trigger the
failure far more often, once every 1 to 2 weeks, two months on the
outside.  The driver guy from Areca is supposed to be working on the
driver for linux, so we'll see if it gets fixed.  It's pretty stable
on a RHEL 5.2 kernel, on anything after that I've tested, it'll hang
every week or two.  So I run RHEL 5.latest with a 5.2 kernel and it
works pretty well.  Note that this is a pretty heavily used machine
with enough access going through 12 drives to use about 30% IOwait,
50% user, 10% sys at peak midday.  Load factor 7 to 15.  And they run
really ultra-smooth between these hangs.  They come back up
uncorrupted, every time, every plug pull test etc.  Other than the
occasional rare hang, they're perfect.