Hi All, I've been tuning a server recently and just today this has started to appear in my top/htop output. [root at db1 ~]# ps -aux | grep kernel root 1011 0.0 0.0 212048 4532 ? Ss 13:34 0:00 /usr/bin/abrt-watch-log -F BUG: WARNING: at WARNING: CPU: INFO: possible recursive locking detected ernel BUG at list_del corruption list_add corruption do_IRQ: stack overflow: ear stack overflow (cur: eneral protection fault nable to handle kernel ouble fault: RTNL: assertion failed eek! page_mapcount(page) went negative! adness at NETDEV WATCHDOG ysctl table check failed : nobody cared IRQ handler type mismatch Machine Check Exception: Machine check events logged divide error: bounds: coprocessor segment overrun: invalid TSS: segment not present: invalid opcode: alignment check: stack segment: fpu exception: simd exception: iret exception: /var/log/messages -- /usr/bin/abrt-dump-oops -xtD I had made a few changes to sysctl.conf which I have now reverted and the error still exists. my sysctl.conf contained; vm.swappiness=0 vm.overcommit_memory=2 vm.overcommit_ratio=90 - this was only added this morning because of an 'out of memory' error in postgresql. kernel.shmmax=35433480192 kernel.shmall=2214592512 which I have now removed. Can anyone shine any light on this? A little search on Google mentions faulty memory, I will install memtest today and see what the output is like. Thanks Michael