Oracle RAC crashing with error "Waited 15 secs for write IO to PST"

Oracle RAC 11g on VMware environment keep crashing, the following errors repeat in the cluster alert log :

"Waited 15 secs for write IO to PST"

 

Solution:

Open ASM spfile and add the following parameter :
_asm_hbeatiowait = 200

The above parameter increase the cluster I/O timeout period.