2013/05/10

Which device is mapped Oracle ASM disk?


Hi,

Yesterday Yuva Kishore is commented on my Oracleasm - Instantiating disk : failed post and asked a question: We can list the asm disks (listdisks) but where can we find the mapping that ASMDISK1 is mapped to /dev/sda1 and so on? 

I want answer this question with this post.

If you  are using ASMLib for configure ASM Disks, then you can use following steps for define which device mapped which ASM Disk.

As you  know, oracleasm listdisks is return only ASM disk names

[grid@oel62-rac1 ~]$ oracleasm listdisks
ASMDISK01
ASMDISK02
ASMDISK03
ASMDISK04
ASMDISK05
[grid@oel62-rac1 ~]$ 

If you want find which ASM disk is mapped which device, then you must use oracleasm querydisk with ASM disk name.

[grid@oel62-rac1 ~]$ oracleasm querydisk -d ASMDISK01
Disk "ASMDISK01"  Is a valid ASM disk On device[8,17] 

As see you, ASMDISK01 is valid ASM disk on device [8,17].

What is means?


It means ASMDISK01 is mapped to device [8,17].

How to find [8,17] device?


We must use Linux ls –l  command as below.

[grid@oel62-rac1 ~]$ ls -l /dev/* | grep 8, | grep 17
brw-rw----  1 root disk  8,  17 Apr 16 15:27 

Now, we can say ASMDISK01 is mapped to /dev/sdb1.

Regards
Mahir M. Quluzade