Re: 2.6.23-rc9-git1 hang with XFS

[David Chinner <dgc@sgi.com>]

On Wed, Oct 03, 2007 at 11:03:29PM +0200, Alessandro Bono wrote:
> Hi all
> 
> I'm testing 2.6.23-rc9-git1 on my old home server
> Trying to reorganizer my xfs filesystem with xfs_fsr cause a sort of system
> hang

xfs_fsr is waiting for a direct I/O to complete.
Other processes are waiting for the superblock I/O to compete
(which is why writes are hanging), an dothers are waiting
for iclog space to be freed up. I think something is holding
off I/O completion, and this:

> possible SYN flooding on port 4664. Sending cookies.
> possible SYN flooding on port 4664. Sending cookies.
> possible SYN flooding on port 4664. Sending cookies.
> possible SYN flooding on port 4664. Sending cookies.
> possible SYN flooding on port 4664. Sending cookies.

indicates someone trying a DOS on your box. Perhaps it's
succeeding by denying interrupt service to you disks?

If you pull the network cable, does the system start to respond
properly again?

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group