Mounting and Dismounting Disk Groups

Mounting and DismountingDisk Groups

    Disk groups that are specified in the ASM_DISKGROUPSinitialization parameter are mounted automatically at ASM instancestartup. This makes them available to all database instancesrunning on the same node as ASM. The disk groups are dismounted atASM instance shutdown. ASM also automatically mounts a diskgroup when you initially create it, and dismounts a disk group ifyou drop it.

    There may be times that you want to mount or dismount diskgroups manually. For these actions use theALTERDISKGROUP...MOUNT orALTER DISKGROUP...DISMOUNTstatement. You can mount or dismount disk groups by name, orspecifyALL.

    If you try to dismount a disk group that contains openfiles, the statement will fail, unless you also specify theFORCE clause.

 

DismountingDisk Groups: Example

The following statement dismounts all disk groups thatare currently mounted to the ASM instance:

ALTER DISKGROUP ALL DISMOUNT;

Mounting Disk Groups:Example

The following statement mounts disk groupdgroup1:

ALTER DISKGROUP dgroup1 MOUNT;

地址：http://docs.oracle.com/cd/B19306_01/server.102/b14200/statements_1006.htm#i2168824

diskgroup_availability::=

diskgroup_availability
 
  Use this clause to make one or more diskgroups available or unavailable to the database instances runningon the same node as the Automatic Storage Management instance.---使用这个语句能确保一个或者多个磁盘组队ASM实例同一个节点的数据库实例的可用或者不可用。

 

Thisclause does not affect the status of the disk group on other nodesin a cluster.---这个子句并不会影响在集群里头的其他节点。
 
MOUNT SpecifyMOUNT to mount the disk groups in the local AutomaticStorage Management instance. SpecifyALLMOUNT to mount all disk groups specified in theASM_DISKGROUPS initialization parameter. Fileoperations can only be performed when a disk group ismounted.
 

See Also:

ASM_DISKGROUPSfor more information about adding disk group names to theinitialization parameter file

 

DISMOUNT Specify DISMOUNT to dismount the specified disk groups. Automatic Storage Management returns an error if any file in the disk group is open unless you also specify FORCE. Specify ALL DISMOUNT to dismount all currently mounted disk groups. File operations can only be performed when a disk group is mounted.FORCE Specify FORCE if you want Automatic Storage Management to dismount the disks even if some files in the disk group are open.