[Top] [All Lists]

Re: XFS over LVM over md RAID

To: xfs@xxxxxxxxxxx
Subject: Re: XFS over LVM over md RAID
From: Michael Monnerie <michael.monnerie@xxxxxxxxxxxxxxxxxxx>
Date: Fri, 10 Sep 2010 02:25:55 +0200
Cc: Richard Scobie <richard@xxxxxxxxxxx>
In-reply-to: <4C89668E.6010800@xxxxxxxxxxx>
Organization: it-management http://it-management.at
References: <4C89668E.6010800@xxxxxxxxxxx>
User-agent: KMail/1.12.4 (Linux/; KDE/4.3.5; x86_64; ; )
On Freitag, 10. September 2010 Richard Scobie wrote:
> Limited testing using dd and bonnie++ shows no difference in write 
> performance
For dd it should always show the same, as you just sequentially write a 
large file. Only with bonnie you would see differences due to stripe 
sets, as the speed only drops when doing I/O not on boundaries and/or 
smaller than the stripe size, as the stripe size is the smallest 
possible I/O for the RAID.

I don't know why you don't see any difference with bonnie though.

FWIW, a stripe set of 256k means you do read/write 256k from a single 
drive on each I/O, then the next 256k from the next drive. I hope you 
have very few small accesses and mostly very large files. If you'd use a 
database on that system it would crawl...

mit freundlichen Grüssen,
Michael Monnerie, Ing. BSc

it-management Internet Services
http://proteger.at [gesprochen: Prot-e-schee]
Tel: 0660 / 415 65 31

****** Aktuelles Radiointerview! ******

// Wir haben im Moment zwei Häuser zu verkaufen:
// http://zmi.at/langegg/
// http://zmi.at/haus2009/

Attachment: signature.asc
Description: This is a digitally signed message part.

<Prev in Thread] Current Thread [Next in Thread>