Coskan’s Approach to Oracle

December 17, 2008

ASMLib and undiscovered disks

Filed under: ASM, Tips — coskan @ 1:03 pm

I won’t give any detailed information but just a quick tip for users who are struggling with discovery of disks they mounted by ASM Lib

If you follow the steps as Tim Halls article ASM using ASMLib and Raw Devices normally everthing should go fine,  but somehow,  if your disks are not discovered, you can first follow very well written ASMLib  troubleshooting guide of Jason Arneil.

If checks are ok,  but disks are still not discovered

you should first try to put ORCL:* (Thanks Saurabh- see the comment) to your ASM disk discovery path

Still doesnt work,   like it did not in my case ?

Try this magical discovery path


If you are lucky as me it will work like charm.


  1. Hi Coskan,

    Putting ORCL:VOL* will not help here as VOL is not the default name in Oracle.

    Instead of ORCL:VOL* it should be ORCL:*.

    Saurabh Sood

    Comment by aaryadba — January 5, 2009 @ 9:51 am

  2. Man, I love you… you made my day…. we were struggling…

    God bless you!


    Comment by Prem — April 18, 2009 @ 6:22 pm

  3. I love U to.
    You save my life. I was stuck in front of the client

    but did you understand why does it works like that and not with ORCL:*

    Comment by Oumen — April 28, 2009 @ 4:12 pm

  4. Man you’re great!
    I was struggling all day getting ASM (with 11gR2!) to work. Just couldn’t get past the create ASM Disk Group window.
    Now it’s running a charm.

    Thanks alot

    Comment by Holger — September 8, 2009 @ 5:42 pm

  5. Thanks!! you are the man!

    Comment by drew — August 28, 2010 @ 4:02 pm

  6. Hi Josh

    There’s a few reasons why you might come across this (use My Oracle Support to find them), but just leaving a quick warning about the ‘/dev/oracleasm/disks’ discovery path. If you have this set, odd things happen to I/O to/from your ASM devices which *may* cause performance degradation and/or other issues. If you haven’t modified SCANORDER/SCANEXCLUDE in particular your disks in /dev/oracleasm/disks will *not* be multipath devices (check the major number of the device to confirm).

    Comment by nlitchfield — December 13, 2013 @ 10:36 am

  7. Thanks it’s work

    Comment by VS — November 20, 2017 @ 7:50 pm

  8. business Owners

    ASMLib and undiscovered disks | Coskan’s Approach to Oracle

    Trackback by business Owners — November 29, 2020 @ 9:38 pm

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