lingu wrote: > Dear all, > > I am getting below syslog error on my oracle database server running on > RHEL4U5. During this time my swap shows zero on both available and free in > the top command output , result in total system hang. can any one guide me > how to fix this issue of memory and exactly what this error indicates?? It indicates that you ran out of memory. 1) add more memory and/or 2) monitor the system closely to determine what is using all of the available memory and either configure it not to, kill it, or don't run it at all. The system sometimes(depending on kernel version) tries to kill processes it thinks might be related to the excessive memory usage, to prevent the total system hang, but it's not always successful. I use nagios for threshold alerting, and it has a handy check_swap monitor, I use it to alert when swap is 5% utilized. For my systems swap is for emergency purposes only. If Oracle is the only real application on that box and if this problem happened suddenly, look at the statspack information (or whatever it's called these days) and try to track down the query that caused the spike in memory usage. I found on a couple of occasions with bad queries in Oracle it could cause memory usage to suddenly spike. Fortunately the system had something like 16gigs of swap on an 8 disk 15k RPM RAID 1+0 that was otherwise not used, so while performance was really slow, the box didn't go down. I think the system had 16gigs of ram. I hope you have at least 16GB of memory, with memory prices these days it's cheap even to have 32GB. Even if you don't allocate it all to Oracle it's useful to help protect against situations like this. nate