X

Alejandro Vargas' Blog

  • March 11, 2007

ORA-15186 NO PST QUORUM MOUNTING ASM

Alejandro Vargas
Technical Leader, ACS Global Delivery, Infrastructure & BigData

On a previous post I did describe another case of problems mounting ASM diskgroups ORA-15080 - 15063 and it's solution.

In this case the Diskgroups failed to mount with error 15186

The problem was related to starting an ASM based BCV on a backup server, ASMLib was able to scan and query correctly the ASM disks, but mounting the ASM disks failed with:

ORA-15186: ASMLIB error function = [asm_open], error = [1], mesg = [Operation not permitted]
ERROR: no PST quorum in group 1: required 2, found 0

The Key to the solution was on Note 309815.1: When EMC's powerpath is used ASMLib can discover the path to the disks in three possible ways, any of the 2 physical disks or the logical multipath device.

ASM must have only one path to the disks; you need to assure that ASM will be able to find only the logical multipath device, that resolve to any of the physical disks.

To do so you need to include on configuration file /etc/sysconfig/oracleasm the following parameters:

ORACLEASM_SCANORDER="multipath sd"
ORACLEASM_SCANEXCLUDE="sdb sdc"

On Oracleasm_scanorder you set first the multipath strings matching your configuration, on Oracleasm_scanexclude you include the physical disks that are not to be discovered, because the path to them is already included on the multipath device.

Another possibility is to explicitly exclude at EMC level the devices to be excluded on the scan, by setting them on the devnode blacklist, ie:

devnode_blacklist {devnode "^sd[a-z][0-9]*"}

Join the discussion

Comments ( 3 )
  • Mathieu Tuesday, March 13, 2007
    Hi, Alejandro.
    A have the same error on a linux server Suse v9 when a t4y to create diskgroup.
    SQL> create diskgroup DG_TEST external redundancy disk 'ORCL:DISK_1';
    create diskgroup DG_TEST external redundancy disk 'ORCL:DISK_1'
    *
    ERROR at line 1:
    ORA-15018: diskgroup cannot be created
    ORA-15072: command requires at least 1 failure groups, discovered only 0
    *****Alert_+ASM.log*****
    create diskgroup DG_TEST external redundancy disk 'ORCL:DISK_1';
    ORA-15186: ASMLIB error function = [asm_open], error = [1], mesg = [Operation not permitted]
    ********
    I can see the disk under asm:
    SQL> select state,header_status,substr(name,1,12) Name,free_mb, substr(path,1,16) PATH from v$asm_disk;
    STATE HEADER_STATU NAME FREE_MB PATH
    -------- ------------ ------------ ---------- ----------------
    NORMAL UNKNOWN 0 ORCL:DISK_1
    NORMAL UNKNOWN 0 ORCL:DISK_4
    NORMAL UNKNOWN 0 ORCL:DISK_3
    NORMAL UNKNOWN 0 ORCL:DISK_2
    Is the header_status = UNKNOWN is normal ?
    I you have any idee !
    Thanks
    Olivier
  • Charles Schultz Thursday, June 28, 2007
    Curious, was this resolved? I am wondering if this is a bug, since the error writeup clearly states that the message is meant for NORMAL redundancy or higher, not external redundancy.
  • Chris Ruel Thursday, May 8, 2008
    Mr. Vargas,
    Thanks for this blog post. It fixed my problem!
    Chris..
Please enter your name.Please provide a valid email address.Please enter a comment.CAPTCHA challenge response provided was incorrect. Please try again.