900804 wrote:This is a bug in Red Hat Enterprise Linux and Oracle Linux. You can fix it manually following the instructions here: https://www.redhat.com/archives/rhelv6-list/2011-February/msg00081.html
Hello everybody, I met this strange behavior. I need to increase shm for larger memory target (dynamically re-sizing server memory) and I am able to achieve it only with manual remount.
Oracle docs recommends the usual way: to put shmfs /dev/shm tmpfs size=8g 0 0 to fstab. But such value is ignored and I always receive 50% of RAM. I have to init 1, remount with mount -t tmpfs shmfs -o size=8g /dev/shm and init 3 again. Why is it so?You do not need to change into single-user mode to change this. Just issue a remount command:
Note however that Oracle Database is not yet certified to run on Oracle Linux 6, so things like this are not part of the standard QA testing. You are better off running database on Oracle Linux 5 Update 7, which is a certified platform and doesn't have this problem.
# mount -o remount,size=8G /dev/shm
It simply removes the -f parameter when mounting /dev/shm in rc.sysinit. Then after a reboot /dev/shm should be sized according to /etc/fstab and you don't have to remount it.
sudo cp /etc/rc.d/rc.sysinit /etc/rc.d/rc.sysinit.bck sudo sed -i 's/-f \/dev\/shm/\/dev\/shm/g' /etc/rc.d/rc.sysinit