--这里的large pool 需要结合自己的业务进行调整
4. ASM 实例和DB 实例之间的关系
Since ASM manages diskgroups and hold the database files and its metadata, a shutdown of the ASM instance will cause all client-database instances to shutdown as well.
In normal shutdowns, the ASM instance will begin shutdown and wait for all sessions to disconnect, just as typical database instances.
Note, however that ASM has a persistent database instance connection, thus the database instances must be shutdown first, in order for ASM to complete shutdown.
--DB 实例先shutdown 之后 ASM 实例才能shutdown
In case of ASM SHUTDOWN IMMEDIATE or ABORT, ASM will immediately terminate any open connections (including the database instance connections), and as a result, all dependent databases will immediately abort; i.e., databases will ungracefully shutdown.
In a single ASM instance configuration, if the ASM instance fails while diskgroups are open for update, ASM instance recovery will be performed upon the restart of ASM by reading the disk group logs.
In RAC environments, with multiple ASM instances sharing disk groups, if one ASM instance should fail, another node’s ASM instance automatically recovers transient ASM metadata changes caused by the failed instance; i.e. performs instance recovery.