By the way the heart beat delays are sort of ignored for external redundancy diskgroup. <<<< PST heartbeat检查会忽略外部冗余的磁盘组。
ASM instance stop issuing more PST heart beat until it succeeds PST revalidation,
but the heart beat delays do not dismount external redundancy diskgroup directly. <<<< PST heartbeat检查即使超过了15秒也不会dismount外部冗余的磁盘组。
The ASM disk could go into unresponsiveness, normally in the following scenarios: <<< ASM磁盘出现无反应的情况通常是由于以下几个原因：
+ Some of the paths of the physical paths of the multipath device are offline or lost <<<< 1.聚合设备下的一些物理路径offline或丢失。
+ During path 'failover' in a multipath set up <<<< 2.具有设备下的物理路径发生failover。
+ Server load, or any sort of storage/multipath/OS maintenance <<<< 3.系统或设备的维护操作。