Same disk no across all the servers

[Kuntal Gupta]

Dear HP-UX Lovers,

I am installing 4 vPars and will present Storage LUNs to all these four servers. Bit the disk name (for the same LUN) is varying server to server.

Eg: The same lun in one server is disk122 and in others disk324, disk134, disk226.

The database team wants same disk name across all the four nodes.

Pls suggest what should be done to keep the disk name same across tyhe servers.

Regards...

Kuntal

[Duncan Edmonstone]

>> The database team wants same disk name across all the four nodes

Is this for Oracle ASM?

If so then I would identify the major /minor numbers for each disk on each system and then use mknod to create specific disks for Oracle ASM's use in a different directory. Then you can make it consistent. e.g. let's say on one system the disk was disk31 - I would do the following:

# ll /dev/rdisk/disk31
crw-r-----   1 bin        sys         13 0x00000f May 11 13:42 /dev/rdisk/disk31

So the major/minor numbers are 13 and 0x00000f - I can now use the mknod command to create something specific for asm:

# mkdir /dev/asm

# chown oracle:dba /dev/asm

# mknod /dev/asm/asmdisk1 c 13 0x00000f

# chown oracle:dba /dev/asm/asmdisk1

You can repeat this on the other vPars and give the ASM disk a consistent name

Now tell your DBAs to set their ASM instance parameter ASM_DISKSTRING to '/dev/asm/asmdisk*'

[Kuntal Gupta]

Dear Mr Duncan,

Thanks a lot for a clear reply.

We will be usning SYBASE, but I believe the concept will be same.

Just one quarry based on the follwing example shown by you:

**********************************************************************************************

# ll /dev/rdisk/disk31
crw-r-----   1 bin        sys         13 0x00000f May 11 13:42 /dev/rdisk/disk31

So the major/minor numbers are 13 and 0x00000f - I can now use the mknod command to create something specific for asm:

# mkdir /dev/asm

# chown oracle:dba /dev/asm

# mknod /dev/asm/asmdisk1 c 13 0x00000f

# chown oracle:dba /dev/asm/asmdisk1

**********************************************************************************************

My understadning:

Here the same device (/dev/rdisk/disk31) is recognised by two dsf namely /dev/rdisk/disk31 and /dev/asm/asmdisk1.

So even if accidentally /dev/rdisk/disk31 is deleted till the system will recognise the disk by /dev/asm/asmdisk1.

Quarry:

Is my understanding is right?

Thanking you in anticipation of your reply.

Best Regards...

Kuntal

[Duncan Edmonstone]

Yes, your understanding is correct - obviously I think a different naming convention and ownership would be appropriate...