Dynamic Multi-Pathing 7.4.1 Administrator's Guide - AIX

To make DMP devices visible to ASM

1. From ASM, make sure ASM_DISKSTRING is set to the correct value:

   /dev/vx/rdmp/*

   For example:

   SQL> show parameter ASM_DISKSTRING;
   NAME                 TYPE        VALUE
   -------------------- ----------- ---------------
   asm_diskstring       string      /dev/vx/rdmp/*

2. As root user, enable DMP devices for use with ASM.

   # vxdmpraw enable username groupname mode [devicename ...]

   where username represents the ASM user running the ASM instance, groupname represents the UNIX/Linux groupname of the specified user-id, and mode represents the permissions to set on the device. If you specify one or more devicenames, DMP support for ASM is enabled for those devices. If you do not specify a devicename, DMP support is enabled for all devices in the system that have an ASM signature.

   For example:

   # vxdmpraw enable oracle dba 765 eva4k6k0_1

   ASM support is enabled. The access permissions for the DMP device are set to the permissions specified by mode. The changes are persistent across reboots.

3. From ASM, confirm that ASM can see these new devices.

   SQL> select name,path,header_status from v$asm_disk;

   NAME  PATH                      HEADER_STATUS
   ---------------------------------------------
   ...   .......                   ....
         /dev/vx/rdmp/eva4k6k0_1   CANDIDATE
   ...   .......                   ....

4. From ASM, increase the Oracle heartbeat wait time from the default value of 15 seconds. To prevent the Oracle application from marking the disk as offline during the DMP failover, increase the default value for _asm_hbeatiowait.

   • For example, to set the value to 360 seconds:

     SQL> alter system set "_asm_hbeatiowait"=360 scope=spfile sid='*';

   • Restart the ASM instance for the new parameter to take effect.