Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller - Mailing list pgsql-performance

From Scott Marlowe
Subject Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller
Date
Msg-id dcc563d10902180031l217d2bcdnffa4c5699580a53a@mail.gmail.com
Whole thread Raw
In response to Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller  (Rajesh Kumar Mallah <mallah.rajesh@gmail.com>)
Responses Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller  (Rajesh Kumar Mallah <mallah.rajesh@gmail.com>)
Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller  (Scott Carey <scott@richrelevance.com>)
List pgsql-performance
On Wed, Feb 18, 2009 at 12:52 AM, Rajesh Kumar Mallah
<mallah.rajesh@gmail.com> wrote:
> the raid10 voulme was benchmarked again
> taking in consideration above points

> Effect of ReadAhead Settings
> disabled,256(default) , 512,1024
>
> xfs_ra0                 414741 ,   66144
> xfs_ra256            403647,  545026                 all tests on sda6
> xfs_ra512            411357,  564769
> xfs_ra1024          404392,  431168
>
> looks like 512 was the best setting for this controller

That's only known for sequential access.
How did it perform under the random access, or did the numbers not
change too much?

> Considering these two figures
> xfs25                   350661,   474481                (/dev/sda7)
> 25xfs                   404291  , 547672                (/dev/sda6)
>
> looks like the beginning of the drives are  15% faster
> than the ending sections , considering this is it worth
> creating a special tablespace at the begining of drives

It's also good because you will be short stroking the drives.  They
will naturally have a smaller space to move back and forth in and this
can increase the random speed access at the same time.

pgsql-performance by date:

Previous
From: Rajesh Kumar Mallah
Date:
Subject: Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller
Next
From: Rajesh Kumar Mallah
Date:
Subject: Re: suggestions for postgresql setup on Dell 2950 , PERC6i controller