Received: from maia.hub.org (maia-4.hub.org [200.46.204.183]) by mail.postgresql.org (Postfix) with ESMTP id 438B2633551 for ; Thu, 6 May 2010 10:36:08 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.183]) (amavisd-maia, port 10024) with ESMTP id 05719-03 for ; Thu, 6 May 2010 13:36:00 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail.int.journyx.com (mail.journyx.com [66.219.41.227]) by mail.postgresql.org (Postfix) with ESMTP id 3E6A3633897 for ; Thu, 6 May 2010 10:36:00 -0300 (ADT) Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.int.journyx.com (Postfix) with ESMTP id 02A48CC005 for ; Thu, 6 May 2010 08:35:58 -0500 (CDT) X-Virus-Scanned: amavisd-new at zimbra.int.journyx.com Received: from mail.int.journyx.com ([127.0.0.1]) by localhost (mail.int.journyx.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id easKUX5-d2ID for ; Thu, 6 May 2010 08:35:47 -0500 (CDT) Received: from mail.int.journyx.com (mail.int.journyx.com [192.168.100.5]) by mail.int.journyx.com (Postfix) with ESMTP id 217FFC4001 for ; Thu, 6 May 2010 08:35:47 -0500 (CDT) Date: Thu, 6 May 2010 08:35:46 -0500 (CDT) From: Scott Whitney Reply-To: Scott Whitney To: pgsql-admin@postgresql.org Message-ID: <15630179.349181273152946840.JavaMail.root@zimbra.int.journyx.com> In-Reply-To: <7965A9DCF12CC14984420BCC37B1608F25AC1C6A3F@Elzar.grant.co.uk> Subject: Re: 6 SCSI Disks RAID 10 x 2 SCSI DISKS RAID1 + 4 SCSI Disks RAID 10 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_17433_5387367.1273152946836" X-Originating-IP: [192.168.100.188] X-Mailer: Zimbra 5.0.18_GA_3012.RHEL4 (ZimbraWebClient - FF3.0 (Win)/5.0.18_GA_3012.RHEL4) X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.909 tagged_above=-10 required=5 tests=BAYES_00=-1.9, HTML_MESSAGE=0.001, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201005/84 X-Sequence-Number: 34557 ------=_Part_17433_5387367.1273152946836 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Well, there are quite a few more variables to consider, including: a) speed of the drives b) battery backed caching controller or not c) throughput of the controller channels d) your particular use Point d is kind of the most important. We've got about 250 customers talking to the same back-end database server with an IBM ServeRaid card. Our O/S is on a RAID 1 while our pgdata (including logs, in our case) is on an external FC array with 14 drives (12 online, 2 HSP, RAID 10). Our performance is pretty good, though we're a bit CPU bound (not I/O bound at this time) due to an older server system. What sort of data/usage you're going to have in that database is pretty important. Heavy SELECT databases have different implications than heavy INSERT databases. So far as the RAID controller goes, so long as it's got 2 or more channels, and the sustained throughput of the card is 100% on each channel, you're fine there. We _did_ find a significant performance increase splitting our O/S and our PostgreSQL data, but *** in our case, at the time of testing *** we did not see an appreciable difference in splitting the logs off to their own volume. ----- "Renato Oliveira" wrote: > > > Good afternoon Guys, I have been reading about RAID for PostgreSQL and some suggestions are: 6 SCSI Disks RAID10 for OS and DB Or 2 SCSI Disks RAID 1 for OS + 4 SCSI RAID 10 for DB I know the more spindles you have the better, but if you are going to be reading and writing to the same volume with a single controller, how good that will be? How do you guys have your RAIDS setup? Thank you Renato Renato Oliveira > Systems Administrator > e-mail: renato.oliveira@grant.co.uk Tel: +44 (0)1763 260811 > Fax: +44 (0)1763 262410 > www.grant.co.uk Grant Instruments (Cambridge) Ltd > > Company registered in England, registration number 658133 > > Registered office address: > 29 Station Road, > Shepreth, > CAMBS SG8 6GB > UK P Please consider the environment before printing this email CONFIDENTIALITY : The information in this e-mail and any attachments is confidential. It is intended only for the named recipients(s). If you are not the named recipient please notify the sender immediately and do not disclose the contents to another person or take copies. VIRUSES: The contents of this e-mail or attachment(s) may contain viruses which could damage your own computer system. Whilst Grant Instruments (Cambridge) Ltd has taken every reasonable precaution to minimise this risk, we cannot accept liability for any damage which you sustain as a result of software viruses. You should therefore carry out your own virus checks before opening the attachment(s). OpenXML : For information about the OpenXML file format in use within Grant Instruments please visit our website ------=_Part_17433_5387367.1273152946836 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable <= div style=3D'font-family: Times New Roman; font-size: 12pt; color: #000000'= >Well, there are quite a few more variables to consider, including:

= a) speed of the drives
b) battery backed caching controller or not
c)= throughput of the controller channels
d) your particular use

Poi= nt d is kind of the most important. We've got about 250 customers talking t= o the same back-end database server with an IBM ServeRaid card. Our O/S is = on a RAID 1 while our pgdata (including logs, in our case) is on an externa= l FC array with 14 drives (12 online, 2 HSP, RAID 10). Our performance is p= retty good, though we're a bit CPU bound (not I/O bound at this time) due t= o an older server system.

What sort of data/usage you're going to ha= ve in that database is pretty important. Heavy SELECT databases have differ= ent implications than heavy INSERT databases.

So far as the RAID con= troller goes, so long as it's got 2 or more channels, and the sustained thr= oughput of the card is 100% on each channel, you're fine there.

We _= did_ find a significant performance increase splitting our O/S and our Post= greSQL data, but *** in our case, at the time of testing *** we did not see= an appreciable difference in splitting the logs off to their own volume. <= br>
----- "Renato Oliveira" <renato.oliveira@grant.co.uk> wrote:
>=20
>=20
>=20

Good afternoon Guys,

 

I have been reading about RAID for PostgreSQL and so= me suggestions are:

 

6 SCSI Disks RAID10 for OS and DB

Or

2 SCSI Disks RAID 1 for OS + 4 SCSI RAID 10 for DB

 

I know the more spindles you have the better, but if= you are going to be reading and writing to the same volume with a single controller= , how good that will be?

 

How do you guys have  your RAIDS setup?

 

Thank you

 

Renato

 

 

 

 

 
Renato= Oliveira
> Systems Administrator
> e-mail: renato.oliveira@gra= nt.co.uk
 
Tel: += 44 (0)1763 260811
> Fax: +44 (0)1763 262410
> www.grant.co.uk
 
Grant = Instruments (Cambridge) Ltd
>  
> Company registered in E= ngland, registration number 658133
>  
> Registered office= address:
> 29 Station Road,
> Shepreth,
> CAMBS SG8 6G= B
> UK
 
 
 
 

 

P Please consider the enviro= nment before printing this email

CONFIDENTIALITY: The = information in this e-mail and any attachments is confidential. It is inten= ded only for the named recipients(s). If you are not the named recipient pl= ease notify the sender immediately and do not disclose the contents to anot= her person or take copies.
 
VIRUSES: The contents= of this e-mail or attachment(s) may contain viruses which could damage you= r own computer system. Whilst Grant Instruments (Cambridge) Ltd has taken e= very reasonable precaution to minimise this risk, we cannot accept liabilit= y for any damage which you sustain as a result of software viruses. You sho= uld therefore carry out your own virus checks before opening the attachment= (s).
 
OpenXML: For informat= ion about the OpenXML file format in use within Grant Instruments please vi= sit our website
------=_Part_17433_5387367.1273152946836--