ASMLib Devices Not Discovered with Diskstring as 'ORCL:*' (Doc ID 1444115.1)

Last updated on OCTOBER 31, 2016

Applies to:

Oracle Database - Enterprise Edition - Version 10.2.0.1 to 11.2.0.3 [Release 10.2 to 11.2]
Linux x86
Linux x86-64
***Checked for relevance on 06-Jan-2014***

Symptoms

Symptom #1]

1. This issue only happens with ASMLib installation on Linux server.

2. ASMLib is installed properly.

# rpm -qa |grep oracleasm

 

oracleasmlib-2.0.4-1.el5
oracleasm-support-2.1.7-1.el5
oracleasm-2.6.18-274.17.1.el5-2.0.5-1.el5
oracleasm-2.6.18-274.17.1.el5-debuginfo-2.0.5-1.el5


3. ASM instance itself can be started but no diskgroup can be mounted with asm_diskstring='ORCL:*'

4. After asm_diskstring is changed to '/dev/oracleasm/disks/*', all ASM devices are visible from v$asm_disk and diskgroups can be mounted.

5. ASMLib disks can be discoverable with the following command as root but not discoverable with grid or oracle user.
  

# /usr/sbin/oracleasm-discover 'ORCL:*'

 

Using ASMLib from /opt/oracle/extapi/64/asm/orcl/1/libasm.so
[ASM Library - Generic Linux, version 2.0.4 (KABI_V2)]
Discovered disk: ORCL:ARCH [318761667 blocks (163205973504 bytes), maxio 512]
Discovered disk: ORCL:DATA [3145719717 blocks (1610608495104 bytes), maxio 512]
Discovered disk: ORCL:FLASH [104856192 blocks (53686370304 bytes), maxio 512]

 


[grid]$ /usr/sbin/oracleasm-discover 'ORCL:*'

 

Unable to open ASMLib


6. The permisssion of ASMLib shows "executable" for others.
   

$ ls -l -rwxr-xr-x 1 root root 18176 Mar 19 2009 /opt/oracle/extapi/*/asm/orcl/1/libasm.so


7. ASM RBAL trace shows the following similar error when ASM instance is stared.
 

   WARNING::lib=/opt/oracle/extapi/64/asm err:8 rc:opendir location:skgdllOpenDi
   errbug=13
   msgbuf=Permission denied other=Permission denied

 

Symptom #2 ]

1. Recently, the following parameters from /etc/sysconfig/oracleasm have been changed and "/etc/init.d/oracleasm scandisks" has been run.

/etc/sysconfig/oracleasm

From

ORACLEASM_SCANORDER=
ORACLEASM_SCANEXCLUDE=


To

ORACLEASM_SCANORDER="dm"
ORACLEASM_SCANEXCLUDE="sd"

If EMC powerpath is used, the value above should be ORACLEASM_SCANORDER="emcpower"

 

2. The following output shows that single path devices have been excluded from discovery path.
 

$ /usr/sbin/oracleasm configure
ORACLEASM_ENABLED=true
ORACLEASM_UID=oracle
ORACLEASM_GID=oinstall
ORACLEASM_SCANBOOT=true
ORACLEASM_SCANORDER="dm"
ORACLEASM_SCANEXCLUDE="sd"

 If EMC powerpath is used, the value above should be ORACLEASM_SCANORDER="emcpower"

 

3. The following output shows that ASMLib devices has been instantiated with single path device. Please note major# as "8".

$ ls -l /dev/oracleasm/disks/*
brw-rw---- 1 oracle oinstall 8, 17 Apr 23 22:53 /dev/oracleasm/disks/CRS1
brw-rw---- 1 oracle oinstall 8, 18 Apr 23 22:53 /dev/oracleasm/disks/DATA1


  Please also note the creation time for ASMLib devices is before the change of ORACLEASM_SCANORDER="dm" and "/etc/init.d/oracleasm scandisks" command is run .

4. v$asm_disk view returns all ASM device information but v$asm_disk.header_status colume shows the status as "UNKNOWN".

SQL> select group_number gn,disk_number dn, mount_status, header_status,mode_status,state, total_mb, free_mb, label, path from v$asm_disk order by group_number, disk_number;

  GN   DN MOUNT_STATUS HEADER_STATU MODE_STATUS  STATE         TOTAL_MB    FREE_MB        LABEL          PATH                                     
---- ---- ----------------------------------------------------------------------------------------------------------------------------------------  
   0    0 CLOSED              UNKNOWN        ONLINE            NORMAL                  0                0       CRS1             ORCL:CRS1  
   0    1 CLOSED              UNKNOWN        ONLINE            NORMAL                  0                0       DATA1           ORCL:DATA1

5. From ASM alert.log, ASM diskgroups are not mounted with ORA-15186 error.

6. On GRID installation, OUI does not show ASMLib devices and ASMLib devices are discoverable only with discovery string "/dev/oracleasm/disks/*".  In this case, it's impossible to check  v$asm_disk.header_status as Oracle ASM is not installed yet.

Cause

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