pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  
help / color / mirror / Atom feed
From: Greg Smith <greg@2ndquadrant.com>
To: Francisco Reyes <lists@stringsutils.com>
Cc: Yeb Havinga <yebhavinga@gmail.com>
Cc: Pgsql performance <pgsql-performance@postgresql.org>
Subject: Re: 10K vs 15k rpm for analytics
Date: Wed, 03 Mar 2010 09:00:32 -0500
Message-ID: <4B8E6B80.9070507@2ndquadrant.com> (raw)
In-Reply-To: <cone.1267584242.708537.32557.1000@shelca>
References: <cone.1267562557.293175.32557.1000@shelca>
	<4B8D7A6C.3010304@gmail.com>
	<cone.1267565315.87109.32557.1000@shelca>
	<4B8DA2D4.8000501@2ndquadrant.com>
	<cone.1267584242.708537.32557.1000@shelca>

Francisco Reyes wrote:
> Who are you using for SAS?
> One thing I like about 3ware is their management utility works under 
> both FreeBSD and Linux well.

3ware has turned into a division within LSI now, so I have my doubts 
about their long-term viability as a separate product as well.

LSI used to be the reliable, open, but somewhat slower cards around, but 
that doesn't seem to be the case with their SAS products anymore.  I've 
worked on two systems using their MegaRAID SAS 1078 chipset in RAID10 
recently and been very impressed with both.  That's what I'm 
recommending to clients now too--especially people who liked Dell 
anyway.  (HP customers are still getting pointed toward their 
P400/600/800.  3ware in white box systems, still OK, but only SATA.  
Areca is fast, but they're really not taking the whole driver thing 
seriously.)

You can get that direct from LSI as the MegaRAID SAS 8888ELP:  
http://www.lsi.com/storage_home/products_home/internal_raid/megaraid_sas/megaraid_sas_8888elp/ 
as well as some similar models.  And that's what Dell sells as their 
PERC6.  Here's what a typical one looks like from Linux's perspective, 
just to confirm which card/chipset/driver I'm talking about:

# lspci -v
03:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS 1078 
(rev 04)
       Subsystem: Dell PERC 6/i Integrated RAID Controller

$ /sbin/modinfo megaraid_sas
filename:       
/lib/modules/2.6.18-164.el5/kernel/drivers/scsi/megaraid/megaraid_sas.ko
description:    LSI MegaRAID SAS Driver
author:         megaraidlinux@lsi.com
version:        00.00.04.08-RH2
license:        GPL

As for the management utility, LSI ships "MegaCli[64]" as a statically 
linked Linux binary.  Plenty of reports of people running it on FreeBSD 
with no problems via Linux emulation libraries--it's a really basic CLI 
tool and whatever interface it talks to card via seems to emulate just 
fine.  UI is awful, but once you find the magic cheat sheet at 
http://tools.rapidsoft.de/perc/ it's not too bad.  No direct SMART 
monitoring here either, which is disappointing, but you can get some 
pretty detailed data out of MegaCli so it's not terrible.

I've seen >100MB/s per drive on reads out of small RAID10 arrays, and 
cleared 1GB/s on larger ones (all on RHEL5+ext3) with this controller on 
recent installs.

-- 
Greg Smith  2ndQuadrant US  Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com   www.2ndQuadrant.us




view thread (47+ messages)  latest in thread

Message-ID: <4B8E6B80.9070507@2ndquadrant.com>
Permalink:  ../4B8E6B80.9070507@2ndquadrant.com/
Also on:    postgresql.org/message-id/4B8E6B80.9070507@2ndquadrant.com

 · 

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-performance@postgresql.org
  Cc: greg@2ndquadrant.com, lists@stringsutils.com, yebhavinga@gmail.com
  Subject: Re: 10K vs 15k rpm for analytics
  In-Reply-To: <4B8E6B80.9070507@2ndquadrant.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox