Fedroa 10 Wedges File System under heavy I/O Load

[Nathan Grennan]

Chuck Forsberg WA7KGX N2469R wrote:
>  From time to time I back up data from /u, /y, and /var onto
> an external IDE HD attached with a USB interface as /dev/sde1.
> The command used is:  cd /; find u y var -print | cpio -pmd /b
> This has worked well until recently.
> 
> Now Fedora "wedges" the /u file system at some time during this
> backup process, which takes about three hours.  If /u doesn't
> wedge before the backup finished with /u, the backup runs
> to completion.
> 
> Strangely enough, even when /u is wedged, other file systems
> on the same drive typically work normally.  Commands such
> as sync and ps -ef wedge, but df does not.
> 
> Any ideas what to look for??

   I have been using ext4 under Fedora 10 on a home desktop, office 
desktop, colo server, and laptop. It has been fine on the office 
desktop, and laptop. Both don't get stressed that much. On the home 
desktop and colo server I have seen this when doing I/O intensive 
things. I have had 1-2 other ext4 issues with the home desktop.

   Ext4 was declared stable by some with 2.6.28, but it has been 
anything but stable. Watching the kernel package changelog, reading 
reports on Slashdot, and talking with the actually developers in 
#fedora-kernel I have learned just how much work is still going into it.

   My experience says don't trust 2.6.27 kernels with ext4, even with 
backported patches. I suspect the backported patches depend on some 
behavior of newer kernels that hasn't been recognized yet. The kernel 
developers have said stay away from 2.6.28. I am currently running 
2.6.29-0.61.rc8.fc10.x86_64. It has been working very well for me.


  I recommend you use the kernel from the url below, and keep track of 
the kernel on koji. cebbert builds rawhide kernels for FC10 on a regular 
basis.

http://koji.fedoraproject.org/koji/buildinfo?buildID=93958