ASM instance startup/shutdown

Managing an ASM instance is no different from managing the typical RDBMS database instances. The ASM instance could be managed by either using a set of SQLPLUS commands or the cluster aware SRVCTL utility. Nevertheless, it is strongly
recommended that you use the SRVCTL utility for managing the (start/stop) ASM instance in an RAC environment.

The ASM instance can be opened either in NOMOUNT, MOUNT, or RESTRICTED modes with the STARTUP command at the SQLPLUS prompt. When you have a planned maintenance on an ASM instance, you can open the ASM instance in a RESTRICT
mode to avoid any possible connections from the database instances. When the ASM instance is opened gracefully, it first discovers the disks and then mounts all the existing disk groups on the local instance.

To shut down the local ASM instance, you can use the various options available with the SHUTDOWN command in the SQLPLUS prompt. The supported options are NORMAL, IMMEDIATE, TRANSACTIONAL, and ABORT. As mentioned previously, you can use the SRVCTL utility to bring down the ASM instance as well. The following list of examples demonstrates how to start up/shut down an ASM instance using SQLPLUS and SRVCTL utilities:

srvctl stop asm –n raclinux1 –o normal:immediate:transactional:abort

export ORACLE_SID=+ASM1
export ORACLE_HOME=$ASM_HOME (in 11gR1)
export ORACLE_HOME=$ORA_GRID_HOME (in 11gR2)
sqlplus / as sysasm
SQL> SHUTDOWN NORMAL:IMMEDIATE:TRANSACTIONAL:ABORT

This example stops the ASM instance on raclinux1 node. Alternatively, you can also use either of the shutdown options.

srvctl start asm –n raclinux1 –o nomount:mount:restrict

export ORACLE_SID=+ASM1
export ORACLE_HOME=$ASM_HOME (in 11gR1)
export ORACLE_HOME=$ORA_GRID_HOME (in 11gR2)
sqlplus / as sysasm
SQL> STARTUP NOMOUNT:MOUNT:RESTRICT

This startup command starts up the ASM instance on raclinux1 node. When you start the instance in NOMOUNT mode, an ASM instance will be started without mounting the existing disk groups. When the instance is started in RESTRICT mode, no database
instance can attach to the ASM instance and all the disk groups are opened in restricted mode too.

Ensure that the database instances that are currently associated with the local ASM instance are stopped prior to shutting down the local ASM instance to avoid encountering an ASM instance shutdown error. In this case, the ASM instance will remain opened. Alternatively, you could use the ABORT option to forcefully shut down the currently connected database's instance before shutting down the ASM instance. It is also strongly recommended to dismount any existing Oracle Cluster File System (ACFS) to avoid any application I/O errors.

Note: If the voting disk and OCR files are placed in a disk group, you will not be able to stop the ASM instance.
In order to stop the ASM instance, you need to stop the cluster.