Ext3 users - Jun 2003 - performance issue with overwritten files

Hi Guys,

I have experienced a recent performance issue with an ext2 filesystem.

Essentially I have had several files that get overwritten on average
once per day.

This has been happening for about a hear when the program accessing and
reading those files started from several milliseconds to 15-20 seconds
to open and read the file.

Moving the directory to a new name and copying the contents solved the
issue.

What could cause such a slowdown to occur?

On Wed, Jun 11, 2003 at 12:35:25PM +1000, Adam Cassar
wrote:
> 
> I have experienced a recent performance issue with an ext2 filesystem.
> 
> Essentially I have had several files that get overwritten on average
> once per day.
> 
> This has been happening for about a hear when the program accessing and
> reading those files started from several milliseconds to 15-20 seconds
> to open and read the file.
> 
> Moving the directory to a new name and copying the contents solved the
> issue.
How big is the directory?  Sounds like you need the htree patches.
These are included in the 2.5 kernel, or they can be applied to the
2.4 tree.  Patches against 2.4.21rc8 can be found here:

	http://thunk.org/tytso/linux/extfs-2.4-update/extfs-update-2.4.21rc8

After you have an htree-enabled kernel, you need to actually enable
the htree feature by running the following commands on the unmounted
filesystem:

	tune2fs -O dir_index /dev/hdXXX
	e2fsck -fD /dev/hdXXXX

I strongly suggest that you upgrade your e2fsprogs to at least versoin
1.30 (1.33 is the latest release of e2fsprogs) before trying to use
the htree ext2/3 feature.

						- Ted