2007-08-09 20:53:53

by Andreas Dilger

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Subject: seekwatcher IO visualization

I saw on #linuxfs today some graphs and movies by Chris Mason showing
the poor IO locality for ext3 compared to btrfs and XFS. It would be
interesting to run this with ext4+mballoc+delalloc, and a separate
one with the FLEXBG feature enabled to see how that improves the
seeking/locality.

http://oss.oracle.com/~mason/seekwatcher/

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.


2007-08-10 03:03:51

by Jose R. Santos

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Subject: Re: seekwatcher IO visualization

On Thu, 9 Aug 2007 14:53:55 -0600
Andreas Dilger <[email protected]> wrote:

> I saw on #linuxfs today some graphs and movies by Chris Mason showing
> the poor IO locality for ext3 compared to btrfs and XFS. It would be
> interesting to run this with ext4+mballoc+delalloc, and a separate
> one with the FLEXBG feature enabled to see how that improves the
> seeking/locality.
>
> http://oss.oracle.com/~mason/seekwatcher/
>
> Cheers, Andreas
> --
> Andreas Dilger
> Principal Software Engineer
> Cluster File Systems, Inc.
>

I was planing to use seekwatcher to look at fsck activity when using
FLEX_BG since I'm already seeing noticeable improvements by using this
feature alone.

We can try other workloads and see how ext4 compares.

-JRS