System hang due to high iowait

[csu4 fedex com]

Hi there,

Could anyone help to find the system hung problem? The box
is running RHEL 3AS Update3. Whenever I do a massive data
transfer (such as rcp from another box to this box), after
certain time (around six to seven hours), this box would
hang up. I could see the top output even it's hung, and it
showed that the iowait is 99% and system contributed another
1% making the server moving nowhere.

The box connected to a HP MSA500 Smart Array Storage, thru
multipath (I enabled it following the user guide) connection.
The filesystem is ext3 format. Any problem here?





Thx & Rgds,


SCHYU