[Top] [All Lists]

Re: How to track down abysmal performance ata - raid1 - crypto - vg/lv -

To: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Subject: Re: How to track down abysmal performance ata - raid1 - crypto - vg/lv - xfs
From: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Date: Wed, 4 Aug 2010 11:13:17 +0200
Cc: linux-raid@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
In-reply-to: <20100804085039.GA11671@xxxxxxxxxxxxx>
Mail-followup-to: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>, Christoph Hellwig <hch@xxxxxxxxxxxxx>, linux-raid@xxxxxxxxxxxxxxx, xfs@xxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
References: <20100804073546.GA7494@xxxxxxxxxxxxxxxxxxxxxxxxxx> <20100804085039.GA11671@xxxxxxxxxxxxx>
User-agent: Mutt/1.5.18 (2008-05-17)

On Wed, Aug 04, 2010 at 04:50:39AM -0400, Christoph Hellwig wrote:
> On Wed, Aug 04, 2010 at 09:35:46AM +0200, Dominik Brodowski wrote:
> > How can I best track down the cause of the performance problem, 
> > a) without rebooting too often, and
> > b) without breaking up the setup specified above (production system)?
> So did you just upgrade the system from an earlier kernel that did not
> show these problems?

No, 2.6.31 to 2.6.34 show similar behaviour.

>  Or did no one notice them before?

Well, there are some reports relating to XFS on MD or RAID, though I couldn't
find a resolution to the issues reported, e.g.

- http://kerneltrap.org/mailarchive/linux-raid/2009/10/12/6490333
- http://lkml.indiana.edu/hypermail/linux/kernel/1006.1/00099.html

However, I think we can rule out barriers, as XFS is mounted "nobarrier"


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