Question:  I am getting this RAC ORA-15064 error:

ORA-15064: communication failure with ASM instance

Trace dumping is performing id=[cdmp_20111118024517]

Instance terminated by ASMB, pid = 12191

I also see this message in my CRS logs:

CRSAPP][1091950912]0StartResource error for ora.jedrac1.ASM1.asm error code = 1
CRSOCR][1500842304]0Resource resname has incomplete attribute set.

Answer: First, see MOSC Note 735804.1 and MOSC Note 239998.1.

The oerr utility shows this for the ORA-15064: communication failure with ASM instance error:

ORA-15064: Communication failure with ASM instance 

Cause: There was a failure to communicate with the ASM instance, most likely because the connection went down.

Action: Check the accompanying error messages for more information on the reason for the failure. Note that database instances will always return this error when the ASM instance is terminated abnormally.

Possible reasons for the "Resource resname has incomplete attribute set" include:

1 - Missing pfile for ASM instance

2 - VIP not working

3 - Software bug

4 - Invalid configuration

5 - Using memory_target improperly:  You are trying to use the MEMORY_TARGET feature. This feature requires the /dev/shm file system to be mounted for at least 285212672 bytes. /dev/shm is either not mounted or is mounted with available space less than this size. Please fix this so that MEMORY_TARGET can work as expected.

6 - ASM hung:  Try bouncing ASM with svrctl stop and svrctl start?

The first workaround for an ASM communication failure is to bounce the ASM instance and check the network for sporadic I/O errors.