RAW ASM

Since we seem to be on the theme of "fellow DBA's" here is another offering:

A fellow DBA has put together the below documentation to help with setting up ASM. He also did a great job on compiling this information:


ASM
1. When using ASM (as of 9/25/08), raw storage is used. Validate the following to make sure that raw storage has been properly configured.
1.1. Raw slices need to exist under /dev/raw.
1.2. Permissions for each raw slice should be set to "oracle:dba".
1.3. The file /etc/sysconfig/rawdevices should contain entries for each raw slice.
1.4. The file /etc/rc.d/rc.local should contain commands to set ownership and permission on each raw slice to be "oracle:dba" and 644, respectively.
1.4.1. There is a bug in Linux startup procedures where /etc/rc.d/rc.local may not be run soon enough, relative to ASM being started. The safest method around this is to update /etc/udev/permissions.d/50-udev.permissions and under "# raw devices" change the line:
raw/*:root:disk:0660

to
raw/*:oracle:dba:0660

2. Before ASM can be used on a server, having someone as "root" run the following:
/u01/app/oracle/product/10.2.0/asm/bin> ./localconfig add

This is for css to be started and added as an auto start service on server reboot, as the last line to /etc/inittab.
3. ASM installation is performed under the "Advanced" installation method in Oracle's installer or, if creating an ASM instance after the software install is done, use "dbca" under ASM's $ORACLE_HOME/bin and choose "Configure Automatic Storage Management" for the operation to perform.
4. NOTE: when using ASM, make sure to set up the server's Oracle listener to run out of ASM's $ORACLE_HOME.
5. For 10g ASM, the install should be directed to /u01/app/oracle/product/10.2.0/asm.
6. After the ASM instance has been created, drop any disk groups created as part of the ASM instance creation, then change the following database parameters:
ALTER SYSTEM SET "_asm_ausize" = 16777216 SCOPE = spfile;
ALTER SYSTEM SET "_asm_stripesize" = 1048576 SCOPE = spfile;

These parameters are needed to be set before any disk groups are created to surpass the limit of 10 TB for any single disk group.
Restart the ASM instance and recreate the 1 disk group using all available disks (external redundancy).

Thx