On Wed, 18 Jan 2006, Fong Vang wrote: > I have a total of 20 CentOS 4.1 systems running on fairly new > hardware. About 6 of them are experiencing strange hangs without > any indication -- nothing in /var/log/messages nor on the console -- > sometime within 10-30 minutes after a reboot. The systems still > responds to ping but you can't ssh to it. At the console, you could > type "root" at the user prompt but it hangs immediately after > hitting enter. > > Memory scan of all systems show no error. > > Any idea how to troubleshoot this problem. The system's not > responsive to do any troubleshooting and nothing abnormal is in the > log. Other folks have hit on the best starting points. For diagnosis, however, you might want to cobble up a cron script that can run every minute: #!/bin/sh # # season to taste... ( top -n 1 -b # also provides a timestamp vmstat iostat ps axf ) >> /var/log/troubleshooting.log 2>&1 The resulting log will be verbose and will grow quickly, but it'll likely contain strong hints of any process-related problems. What it won't do, of course, is provide indications of hardware faults. -- Paul Heinlein <> heinlein at madboa.com <> www.madboa.com