Mapeamento de discos ASM para dispositivos físicos.

 

site original:

https://blogs.oracle.com/AlejandroVargas/entry/mapping_asm_disks_to_physical

Mapping ASM disks to Physical Devices

By AVargas-Oracle on Nov 15, 2007

Sometimes you may need to map ASM Disks to its physical devices.
If they are based on ASMLib you will see their ASM name, ie: ORCL:VOL1 when querying v$asm_disk

When running oracleasm querydisk VOL1 you will get in addition the major – minor numbers, that can be used to match the physical device, ie:

[root@orcldb2 ~]# /etc/init.d/oracleasm querydisk VOL1
Disk “VOL1” is a valid ASM disk on device [8, 97]

[root@orcldb2 ~]# ls -l /dev | grep 8, | grep 97
brw-rw—-   1 root disk     8,      81 Nov  4 13:02 sdg1

This script can do the job for a group of ASM Disks:

———- start  here ————
#!/bin/ksh
for i in `/etc/init.d/oracleasm listdisks`
do
v_asmdisk=`/etc/init.d/oracleasm querydisk $i | awk  ‘{print $2}’`
v_minor=`/etc/init.d/oracleasm querydisk $i | awk -F[ ‘{print $2}’| awk -F] ‘{print $1}’ | awk ‘{print $1}’`
v_major=`/etc/init.d/oracleasm querydisk $i | awk -F[ ‘{print $2}’| awk -F] ‘{print $1}’ | awk ‘{print $2}’`
v_device=`ls -la /dev | grep $v_minor | grep $v_major | awk ‘{print $10}’`
echo “ASM disk $v_asmdisk based on /dev/$v_device  [$v_minor $v_major]”
done
———- finish here ————

The output looks like this:

ASM disk “VOL1” based on /dev/sdg1  [8, 97]
ASM disk “VOL10” based on /dev/sdp1  [8, 241]
ASM disk “VOL2” based on /dev/sdh1  [8, 113]
ASM disk “VOL3” based on /dev/sdk1  [8, 161]
ASM disk “VOL4” based on /dev/sdi1  [8, 129]
ASM disk “VOL5” based on /dev/sdl1  [8, 177]
ASM disk “VOL6” based on /dev/sdj1  [8, 145]
ASM disk “VOL7” based on /dev/sdn1  [8, 209]
ASM disk “VOL8” based on /dev/sdo1  [8, 225]
ASM disk “VOL9” based on /dev/sdm1  [8, 193]

If you are using multi-path, you will need an additional step to map the physical device to the multi-path device, for instance if using EMC Powerpath if you want to map sdf1

[root@orclp ~]# /etc/init.d/oracleasm querydisk vol1
Disk “VOL1” is a valid ASM disk on device [8, 81]

[root@orclp ~]# ls -l /dev | grep 8,| grep 81
brw-rw—-   1 root disk     8,      81 Oct 29 20:42 sdf1

[root@orclp ~]# powermt display dev=all
…
…
Pseudo name=emcpowerg
Symmetrix ID=000290101698
Logical device ID=0214
state=alive; policy=SymmOpt; priority=0; queued-IOs=0
==============================================================================
—————- Host —————   – Stor –   — I/O Path –  — Stats —
### HW Path                 I/O Paths    Interf.   Mode    State  Q-IOs Errors
==============================================================================
1 qla2xxx                   sdf       FA  7bB   active  alive      0      0
2 qla2xxx                   sdq       FA 10bB   active  alive      0      0
…
…

The last step is to check the partition assigned to the emcpower device, ie:

[root@orclp ~]# ls -l /dev/emcpowerg*
brw——-  1 root root 120, 96 Oct 29 20:41 /dev/emcpowerg
brw——-  1 root root 120, 97 Nov 15 13:08 /dev/emcpowerg1