Why does lun show different size on different rac nodes?

Question

Hi all,
We are trying to increase ASM disk space and with respect to it when we are trying to allocate more space this question came across my mind. Now this was previously configured by my previous SA.
[root@oracledbtest1 ~]# /etc/init.d/oracleasm querydisk -d `/etc/init.d/oracl
cut -f2,10,11 -d" " | perl -pe 's/"(.*)".*\[(.*), *(.*)\]/$1 $2 $3/g;' |
while read v_asmdisk v_minor v_major
do
v_device=`ls -la /dev | grep " $v_minor, *$v_major " | awk '{print $10}'`
echo "ASM disk $v_asmdisk based on /dev/$v_device [$v_minor, $v_major]"
done
**ASM disk ASM01 based on /dev/dm-15 [253, 15]**
**ASM disk ASM02 based on /dev/dm-14 [253, 14]**
node 2:
[root@oracledbtest1 ~]# /etc/init.d/oracleasm querydisk -d `/etc/init.d/oracleasm listdisks -d` |
cut -f2,10,11 -d" " | perl -pe 's/"(.*)".*\[(.*), *(.*)\]/$1 $2 $3/g;' |
while read v_asmdisk v_minor v_major
do
v_device=`ls -la /dev | grep " $v_minor, *$v_major " | awk '{print $10}'`
echo "ASM disk $v_asmdisk based on /dev/$v_device [$v_minor, $v_major]"
done
**ASM disk ASM01 based on /dev/dm-13 [253, 13]**
**ASM disk ASM02 based on /dev/dm-14 [253, 14]**
Now, can any one help me in telling why are my LUN's showing different sizes on RAC and also the best way to allocate the space to the disks in the above scenario.
P.S I am fairly new in posting to the OTN. Please excuse if I am not clear with my question.
Edited by: 902932 on Apr 8, 2013 8:25 AM

Answer 1

why you think the space is different between the 2 nodes?
The devices are different, that's ok, dm- is the device mapper name, and several devices will create dm-* like entries, so it's ok to have them different.
When you add a disk, you should follow an approach like:
Present the disk on the storage
Refresh the luns on all the nodes
Create the oracleasm disk on one node
refresh the oracleasm disks on all the nodes
verify the new oracleasm disk is present on all nodes in /dev/oracleasm/disks/*
At this point, you can use asmca or sqlplus in the +ASMn instance to make your asm diskgroup to grow, or create a new disk group