Re: Dell PowerEdge 2950 performance

Luke,

For some reason it looks like bonnie is picking a 300M file.

> bonnie++ -d bonnie
Version 1.03 ------Sequential Output------ --Sequential Input-
--Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block--
--Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP
/sec %CP
300M 179028 99 265358 41 270175 57 167989 99 +++++ +++
+++++ +++
------Sequential Create------ --------Random
Create--------
-Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
/sec %CP
16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
+++++ +++
,300M,179028,99,265358,41,270175,57,167989,99,+++++,+++,+++++,+++,16,+++
++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++,+++++,+++

So here's results when I force it to use a 16GB file, which is twice the
amount of physical ram in the system:

> bonnie++ -d bonnie -s 16000:8k
Version 1.03 ------Sequential Output------ --Sequential Input-
--Random-
-Per Chr- --Block-- -Rewrite- -Per Chr- --Block--
--Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP
/sec %CP
16000M 158539 99 244430 50 58647 29 83252 61 144240 21
789.8 7
------Sequential Create------ --------Random
Create--------
-Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
/sec %CP
16 7203 54 +++++ +++ +++++ +++ 24555 42 +++++ +++
+++++ +++
,16000M,158539,99,244430,50,58647,29,83252,61,144240,21,789.8,7,16,7203,
54,+++++,+++,+++++,+++,24555,42,+++++,+++,+++++,+++

... from Vivek...
which is an issue with freebsd and bonnie++ since it doesn't know
that freebsd can use large files natively (ie, no large file hacks
necessary). the freebsd port of bonnie takes care of this, if you
use that instead of compiling your own.
...

Unfortunately I had to download and build by hand, since only bonnie++
1.9x is available in BSD 6.1 ports when I checked.

One other question- would the following also be mostly a test of RAM? I
wouldn't think so since it should force it to sync to disk...
time bash -c "(dd if=/dev/zero of=/data/bigfile count=125000 bs=8k &&
sync)"

Oh, and while I'm thinking about it, I believe Postgres uses 8k data
pages correct? On the RAID, I'm using 128k stripes. I know there's been
posts on this before, but is there any way to tell postgres to use this
in an effective way?

Thanks,

Bucky

-----Original Message-----
From: pgsql-performance-owner(at)postgresql(dot)org
[mailto:pgsql-performance-owner(at)postgresql(dot)org] On Behalf Of Vivek Khera
Sent: Tuesday, August 15, 2006 3:18 PM
To: Pgsql-Performance ((E-mail))
Subject: Re: [PERFORM] Dell PowerEdge 2950 performance

On Aug 15, 2006, at 2:50 PM, Luke Lonergan wrote:

> I don't know why I missed this the first time - you need to let
> bonnie++
> pick the file size - it needs to be 2x memory or the results you
> get will
> not be accurate.

which is an issue with freebsd and bonnie++ since it doesn't know
that freebsd can use large files natively (ie, no large file hacks
necessary). the freebsd port of bonnie takes care of this, if you
use that instead of compiling your own.