Oracle Database Discussions

Oracle 11.2
OS: RedHat Linux 5.5

Hi Gurus,

1. what is the difference (either performace wise or others) between using tmpfs as a mount point against shmfs for oracle AMM(memory_target).
mount -t tmpfs tmpfs -o size=4g /dev/shm
mount -t tmpfs shmfs -o size=4g /dev/shm

I thinks there should not be any difference since both mounting /dev/shm. what do you think about it.

2. will there be any negative or positive impact on the OS system or Oracle DB , if both tmpfs and shmfs is use to mount /dev/shm as the same time?
e.g df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 99M 12M 83M 12% /boot
tmpfs 700M 312M 389M 45% /dev/shm
shmfs 700M 312M 389M 45% /dev/shm

3. shmfs file system not in Red Hat Enterprise Linux 4 or 5:
what is the implication for Oracle 11g if ONLY tmpfs mount point exist? and AMM is implemented.
Filesystem Size Used Avail Use% Mounted on
tmpfs 700M 312M 389M 45% /dev/shm


thks..

Edited by: teits on Feb 25, 2012 10:31 AM