11R2 RAC ASM disk creation on AIX-IBM

Oracle ASM need to maintain the SAN disks across all nodes in the ASM cluster but sometimes or always the naming convention is not changeable since it is controlled by the OS kernel. To overcome this issue, we need to create a disk device and link it to the original SAN disk assigned. This disk device created must have same naming in all nodes and linked to the same disk ID in all nodes as well.

Procedure:

1. configure the new SAN disks (assuming EMC)
% cfgmgr

2. Get the IDs and reserve_lock to be No

%lquerypv -h /dev/rdiskpowerXX ( to Check if it is part of Diskgroup)

% chdev -l hdiskpowerXX -a reserve_lock=no

3. Get major/minor number of SAN disk assigned
% ls -l /dev/hdiskpower9
brw-rw---- 1 root system 44, 9 Jun 29 16:12 /dev/hdiskpower9
major number is 44
minor number is 9

4. create the ASM disk which must be a character device
% mknod /dev/asmdisk00XX c 44 9

5. change ownership of the ASM device to be oracle:oinstall
% chown oracle:oinstall /dev/asmdisk00XX

6. change the permission of the ASM disk to be 765
% chmod 765 /dev/asmdisk00XX

7. change ownership of the hdiskpower character device to be oragrid:oinstall
% chown oragrid:oinstall /dev/rhdiskpower9

8. In the other nodes, you must do the same thing with hdiskpower device that have the same ID as hdiskpower9