Hey, y'all! :) I've got an RHEL-4 server (yep, I know it's not CentOS, but hey we gotta send some money RH's way to keep CentOS up and going! ) that's running Oracle 10g. This same hardware worked just fine for over a year running RHEL-AS-2.1 and Oracle 9i. Now we're getting spontaneous reboots when running oracle processes that eat up a bunch of resources. I don't know where to go from here. It's got dual hyper-threading processors set to hyperthreading mode, and I understand that the 2.6 kernel used to have HT issues, but I thought that'd been solved. The kernel we're running is: 2.6.9-22.0.2.ELsmp (yeah, not the latest, I haven't had a chance lately to test and update the patches). I think the kernel settings are correct, what with 4gigs of ram: [root at sibrsdbs etc]# cat sysctl.conf # Kernel sysctl configuration file for Red Hat Linux # # For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and # sysctl.conf(5) for more details. # Controls IP packet forwarding net.ipv4.ip_forward = 0 # Controls source route verification net.ipv4.conf.default.rp_filter = 1 # Do not accept source routing net.ipv4.conf.default.accept_source_route = 0 # Controls the System Request debugging functionality of the kernel kernel.sysrq = 0 # Controls whether core dumps will append the PID to the core filename. # Useful for debugging multi-threaded applications. kernel.core_uses_pid = 1 # oracle settings kernel.shmall = 2097152 kernel.shmmax = 2147483648 kernel.shmmni = 4096 kernel.sem = 250 32000 100 128 #fs.file-max = 65536 net.ipv4.ip_local_port_range = 1024 65000 net.core.rmem_default=262144 net.core.wmem_default=262144 net.core.rmem_max=262144 net.core.wmem_max=262144 I don't know how to look for the core dump, if there was one. I don't see anything named 'core' in the /root directory. I'm sucking wind, any suggestions? Thanks! Ben