Message-ID: <42E128BD.2000104@commandprompt.com>
Date: Fri, 22 Jul 2005 10:11:25 -0700
From: "Joshua D. Drake" <jd@commandprompt.com>
Organization: Command Prompt, Inc.
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To: Patrick Welche <prlw1@newn.cam.ac.uk>
Cc: Luke Lonergan <llonergan@greenplum.com>,
	Mark Wong <markw@osdl.org>, Andrew Dunstan <andrew@dunslane.net>,
	Alvaro Herrera <alvherre@surnet.cl>,
	Bruce Momjian <pgman@candle.pha.pa.us>,
	Alon Goldshuv <agoldshuv@greenplum.com>,
	pgsql-performance@postgresql.org, maryedie@osdl.org
Subject: Re: [PATCHES] COPY FROM performance improvements
References: <42E05FAF.70601@commandprompt.com>
	<BF05C1C8.9702%llonergan@greenplum.com>
	<20050722164905.GE18413@quartz.newn.cam.ac.uk>
In-Reply-To: <20050722164905.GE18413@quartz.newn.cam.ac.uk>
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Here is the SCSI output:

Web Server

SCSI subsystem driver Revision: 1.00
megaraid: v1.18j (Release Date: Mon Jul  7 14:39:55 EDT 2003)
megaraid: found 0x1028:0x000f:idx 0:bus 4:slot 3:func 0
scsi0 : Found a MegaRAID controller at 0xf883f000, IRQ: 18
scsi0 : Enabling 64 bit support
megaraid: [412W:H406] detected 1 logical drives
megaraid: supports extended CDBs.
megaraid: channel[1] is raid.
megaraid: channel[2] is raid.
scsi0 : LSI Logic MegaRAID 412W 254 commands 15 targs 5 chans 7 luns


Database Server

SCSI subsystem driver Revision: 1.00
megaraid: v1.18j (Release Date: Mon Jul  7 14:39:55 EDT 2003)
megaraid: found 0x101e:0x1960:idx 0:bus 5:slot 0:func 0
scsi0 : Found a MegaRAID controller at 0xf883f000, IRQ: 21
scsi0 : Enabling 64 bit support
megaraid: [196T:3.33] detected 1 logical drives
megaraid: supports extended CDBs.
megaraid: channel[1] is raid.
megaraid: channel[2] is raid.
scsi0 : LSI Logic MegaRAID 196T 254 commands 15 targs 5 chans 7 luns
Starting timer : 0 0
blk: queue c5f2d218, I/O limit 4095Mb (mask 0xffffffff)
scsi0: scanning virtual channel 0 for logical drives.
   Vendor: MegaRAID  Model: LD 0 RAID5   86G  Rev: 196T
   Type:   Direct-Access                      ANSI SCSI revision: 02
Starting timer : 0 0


The webserver is a 1U and it actually performs better on the IO than the 
database server even though the database server is running 6 disks versus 3.

The database server is a PE (Power Edge) 6600

Database Server IO:

[root@master root]# /sbin/hdparm -tT /dev/sda

/dev/sda:
  Timing buffer-cache reads:   1888 MB in  2.00 seconds = 944.00 MB/sec
  Timing buffered disk reads:   32 MB in  3.06 seconds =  10.46 MB/sec

Second Database Server IO:

[root@pq-slave root]# /sbin/hdparm -tT /dev/sda

/dev/sda:
  Timing buffer-cache reads:   1816 MB in  2.00 seconds = 908.00 MB/sec
  Timing buffered disk reads:   26 MB in  3.11 seconds =   8.36 MB/sec
[root@pq-slave root]#

Which is just horrible.


Sincerely,

Joshua D. Drake


Patrick Welche wrote:
> On Thu, Jul 21, 2005 at 09:19:04PM -0700, Luke Lonergan wrote:
> 
>>Joshua,
>>
>>On 7/21/05 7:53 PM, "Joshua D. Drake" <jd@commandprompt.com> wrote:
>>
>>>Well I know that isn't true at least not with ANY of the Dells my
>>>customers have purchased in the last 18 months. They are still really,
>>>really slow.
>>
>>That's too bad, can you cite some model numbers?  SCSI?
> 
> 
> I would be interested too, given
> 
>    http://www.netbsd.org/cgi-bin/query-pr-single.pl?number=30531
> 
> 
> Cheers,
> 
> Patrick
> 
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