Re: ASM and EMC PowerPath

From: Radoulov, Dimitre <>
Date: Sun, 10 Apr 2011 11:13:51 +0200
Message-ID: <>

Hi Leyi,
answers inline.

> What my point is , since you can get this result:
>> # /etc/init.d/oracleasm querydisk -p BLOB
>> Disk "BLOB" is a valid ASM disk
>> /dev/sdam1: LABEL="BLOB" TYPE="oracleasm"
>> /dev/sdbc1: LABEL="BLOB" TYPE="oracleasm"
>> /dev/emcpowerz1: LABEL="BLOB" TYPE="oracleasm"
> Then it means emcpower device was used when creatediesk. Actually, no
> matter what device name was used when createdisk, at least now your
> "/dev/emcpowerz1" is recognized as ASM Disk BLOB. it's enough (If I'm
> wrong please correct me).

Actually, that's what my original email is all about.

I see that the emcpower devices are recognized as asm disks, I don't know if this is enough though ...

I suppose that querydisk just reports all devices/paths that point to the physical disk. What I want to know is if asm is smart enough to pick the emcpower device in this case or it just uses the first one found (in ASCIIbetical order).

querydisk -d returns the major/minor of one of the physical paths to the disk, not the emcpower path (I checked /proc/partitions for that), that's why I think it actually doesn't use the logical devices. I say "I think", because I'm not finding this anywhere in the docs for now.

> Query disk typically is safe, you can modify "ORACLEASM_SCANORDER" and
> "ORACLEASM_SCANEXCLUDE" when you get some downtime in database
> maintenance window then restart ASM, if disk scanned is not an ASM
> disk, will just simply raise an error, no data broken. (Of course,
> backup your database first)

Thanks for the suggestion!
Yes, most likely we'll try this first.

> BTW, can you post /proc/partitions content?

I'm attaching the content of /proc/partitions.

Thank you!

Best regards


Received on Sun Apr 10 2011 - 04:13:51 CDT

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