TOD – How to check if a LUN is used by ASM September 3, 2008
Posted by grumpydba in ASM, Tip 'o the day.Tags: ASM lun
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ASM is down, init+ASM.ora is gone and you need to see which luns are owned by ASM, if on linux you can generally use the “service oracleasm” command to find the luns that have been marked for use with ASM. On other platforms the oracleasm service is not available, how then to check? You can use the od command to check the first few lines of a lun, it will display “ORCLDISK” and the diskgroup in the first five lines if part of and ASM diskgroup:
/dev:()$ od -c /dev/hdiskpower10 | more 0000000 202 001 001 200 211 341 $ 207 0000020 0000040 O R C L D I S K 0000060 0000100 \n 020 001 003 D G R O U P 1 _ 0000120 0 0 0 0 0000140 D G R O U P 1 0000160 0000200 D G R O U P 1 _ 0000220 0 0 0 0 0000240
You can see above that this lun is part of diskgroup dgroup1.
