Archive for June, 2014

Oracle 11g ASM disk discovery

June 12, 2014 Leave a comment

During the installation of Oracle 12c on Oracle enterprise linux  I noticed  an  incorrect default setting for ASM disk discovery when using ASM lib. The discovery path is set to ‘/dev/raw/sd*’, which is incorrect because ASM lib creates the devices under ‘/dev/oracleasm/disks’.

so make sure yo change the disk discovery path to /dev/oracleasm/disks



Categories: Oracle

ORA-00845: MEMORY_TARGET not supported on this system

June 12, 2014 Leave a comment

encountered the oracle error “ORA-00845: MEMORY_TARGET not supported on this system” on a 12c database recently and occurs when an instance tries to use AMM and tmpfs mount point is less than the value specified  in  parameter memory_max_target

to solve this issue we need to  unmount the tmpfs and mount with increased space for tmps and make sure that this change is made permanent by adding the enty in /etc/fstab

As root

# unmount  tmpfs

umount: /dev/shm: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))

# umount -l tmpfs

# mount -t tmpfs tmpfs -o size=10240m /dev/shm

# vi /etc/fstab

# cat /etc/fstab

tmps       /dev/shm        tmpfs    size=10240m    0    0

# exit


Categories: Oracle Rac