Starting Up an Oracle ASM Instance
- Connecting
To and Starting Up an Oracle ASM Instance
- Starting Up an Oracle ASM instance with an Incorrect
SPFILE Path
- About Mounting Disk Groups at Startup
- About Restricted Mode
You start an Oracle ASM instance similarly to the way in
which you start an Oracle database instance with some minor differences.
When starting an Oracle ASM instance, note the following:
- To connect to a local
Oracle ASM instance with SQL*Plus, set the ORACLE_SID environment variable to the
Oracle ASM system identifier (SID).
The default Oracle ASM SID for a single-instance database is +ASM, and the default SID for Oracle ASM for an Oracle RAC node is +ASMnode_number where node_number is the number of
the node. The ORACLE_HOME environment variable must be set to the Grid
Infrastructure home where Oracle ASM was installed.
Note:
Oracle recommends that you do not change the default
Oracle ASM SID name.
- The initialization
parameter file must contain the following entry:
INSTANCE_TYPE = ASM
This parameter indicates that an Oracle ASM instance, not a
database instance, is starting.
- When you run the STARTUP command, rather than trying to mount and open a database, this
command attempts to mount Oracle ASM disk groups.
For information about disk groups that are mounted at startup
time, see "About Mounting Disk Groups at Startup".
After the Oracle ASM instance has started, you can mount disk
groups with the ALTER
DISKGROUP...MOUNT command. See "Mounting and Dismounting Disk Groups" for more information.
- The associated Oracle
database instance does not have to be running when you start the
associated Oracle ASM instance.
The following list describes how Oracle ASM interprets SQL*Plus STARTUP command parameters.
- FORCE Parameter
Issues a SHUTDOWN
ABORT to the Oracle ASM instance before
restarting it.
If an Oracle Automatic Storage Management Cluster File System
(Oracle ACFS) file system is currently mounted on Oracle ADVM volumes, the file
system should first be dismounted. Otherwise, applications encounter I/O errors
and Oracle ACFS user data and metadata may not be written to storage before the
Oracle ASM storage is fenced. For information about dismounting an Oracle ACFS
file system, MOUNT or OPEN Parameter
Mounts the disk groups specified in the ASM_DISKGROUPS initialization parameter. This is the default if no command
parameter is specified.
- NOMOUNT Parameter
Starts up the Oracle ASM instance without mounting any disk
groups.
- RESTRICT Parameter
Starts up an instance in restricted mode that enables access
only to users with both the CREATE SESSION and RESTRICTED SESSION system privileges. You can use the RESTRICT clause in combination with the MOUNT, NOMOUNT, and OPEN clauses.
In restricted mode, database instances cannot use the disk
groups. In other words, databases cannot open files that are in that disk
group. Also, the disk group cannot be mounted by any other instance in the
cluster. Mounting the disk group in restricted mode enables only one Oracle ASM
instance to mount the disk group. This mode is useful to mount the disk group
for repairing configuration issues.
The following is a sample SQL*Plus session for starting an
Oracle ASM instance.
SQLPLUS /NOLOG
SQL> CONNECT SYS AS SYSASM
Enter password: sys_password
Connected to an idle instance.
SQL> STARTUP
ASM instance started
Total System Global Area 71303168 bytes
Fixed Size 1069292 bytes
Variable Size 45068052 bytes
ASM Cache 25165824 bytes
ASM disk groups mounted
If the SPFILE path in the GPNP profile is incorrect, you
can start the Oracle ASM instance as follows:
- Create a PFILE with one
line in it that identifies the path to the SPFILE.
For example:
Create the /u01/oracle/dbs/spfileasm_init.ora file that contains:
SPFILE='+DATA/asm/asmparameterfile/asmspfile.ora'
- Start up the instance using
the initialization parameter file.
For example:
SQL> STARTUP PFILE=/u01/oracle/dbs/spfileasm_init.ora
- After the instance is
running, use the ASMCMD spset command to update the SPFILE path in the
GPNP profile. See "spset".
For example:
ASMCMD> spset +DATA/asm/asmparameterfile/asmspfile.ora
- Disk groups specified in
the ASM_DISKGROUPS initialization parameter
- Disk group used by Cluster
Synchronization Services (CSS) for voting files
- Disk groups used by Oracle
Clusterware for Oracle Cluster Registry (OCR)
- Disk group used by the
Oracle ASM instance to store the ASM server parameter file (SPFILE)
If no disk groups are found in the previous list, then the
Oracle ASM instance does not mount any disk groups at startup. After the Oracle
ASM instance has started, you can mount disk groups with the ALTER DISKGROUP...MOUNT command.
You can use the STARTUP RESTRICT command to control access to an Oracle ASM instance
while you perform maintenance. When an Oracle ASM instance is active in this
mode, all of the disk groups that are defined in the ASM_DISKGROUPS parameter are mounted in RESTRICTED mode. This
prevents databases from connecting to the Oracle ASM instance. In addition, the
restricted clause of the ALTER SYSTEM statement is disabled for the Oracle ASM instance. The ALTER DISKGROUP diskgroup MOUNT statement is extended to enable Oracle ASM to mount a
disk group in restricted mode.
When you mount a disk group in RESTRICTED mode, the disk
group can only be mounted by one instance. Clients of Oracle ASM on that node
cannot access that disk group while the disk group is mounted in RESTRICTED mode. The RESTRICTED mode enables you to perform maintenance tasks on a disk
group in the Oracle ASM instance without interference from clients.
Rebalance operations that occur while a disk group is in RESTRICTED mode eliminate the lock and unlock extent map messaging that
occurs between Oracle ASM instances in an Oracle RAC environment. This improves
the overall rebalance throughput. At the end of a maintenance period, you must
explicitly dismount the disk group and remount it in normal mode.
Confirm that the Oracle ASM instance is running.
For example:
$ srvctl status listener
$ srvctl status asm
Otherwise, start the Oracle ASM instance with SRVCTL.
For example:
$ srvctl start asm
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