Hi Wayne, Thanks a lot for the tips. I did have a try: 1. If the file system is ext2 for the large IO operation, then your work around works; 2. If the file system is ext3, then it hangs again. I'm wondering if this is ext3 problem or the parameter you mentioned must be adjusted for ext3? Thx & Rgds, schyu Wayne Pinette <Wpinette@xxxxxxxxxx To: redhat-list@xxxxxxxxxx .ca> cc: Sent by: Subject: Re: System hang due to high iowait redhat-list-bounces@ redhat.com 2004-10-04 23:19 Please respond to General Red Hat Linux discussion list I had a similar problem and did a google search on it a while back. I found this little snippet and tried it and have never had a problem since : In your rc.d/rc.local file append the following two lines : echo 100 > /proc/sys/vm/inactive_clean_percent echo 2 10 20 > /proc/sys/vm/pagecache I would give this a try. Wayner >>> csu4@xxxxxxxxx 04/10/2004 1:46:04 am >>> 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 -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list