Support of Oracle RAC ASM with SGeRAC, January 2008

HP Availability Clusters Solutions Lab 1/25/2008 Page 10

# lvcreate -n lvol1 vgora_asm

# lvcreate -n lvol2 vgora_asm

# lvchange -C y /dev/vgora_asm/lvol1

# lvchange -C y /dev/vgora_asm/lvol2

# Assume vgdisplay shows each PV has 2900 extents in our example

# lvextend -l 2900 /dev/vgora_asm/lvol1 /dev/dsk/c9t0d1

# lvextend -l 2900 /dev/vgora_asm/lvol2 /dev/dsk/c9t0d2

# Assume a PV timeout of 30 seconds.

# There are 2 paths to each PV, so the LV timeout value is 60 seconds

# lvchange -t 60 /dev/vgora_asm/lvol1

# lvchange -t 60 /dev/vgora_asm/lvol2

# dd if=/dev/zero of=/dev/vgora_asm/rlvol1 bs=8192 count=12800

3. Export the volume group across the SGeRAC cluster and mark it as shared, as specified by

SGeRAC documentation.

Assign the right set of ownerships and access rights to the raw logical

volumes on each node as required by Oracle (oracle:dba and 0660, respectively).

We can now use the raw logical volume device names as disk group members when configuring

ASM disk groups using the Oracle database management utilities. There are a number of ways of

doing this described in Oracle ASM documentation, including the dbca database creation wizard as

well as sqlplus.

The same command sequence, with some modifications, can be used for adding new disks to an

already existing volume group that is being used by ASM to store one or more RAC databases. If the

database(s) should be up and running during the operation, we use the Single Node Online volume

Reconfiguration (SNOR) feature of SLVM.

Step 1 of the above sequence is modified as follows:

• First, deactivate the volume group vgora_asm on all nodes but one, say node A. This

requires prior shutdown of the database(s) using ASM-managed storage and ASM itself, on

all nodes but node A. See the section ASM Halt is needed to ensure disconnect of ASM

from SLVM Volume Groups to understand why it is not adequate to shut down only the

database(s) using the volume group to be reconfigured, and why we must shut down ASM

itself and therefore all database(s) using ASM-managed storage, on all nodes but node A.

• Next, on node A, switch the volume group to exclusive mode, using SNOR.

• Initialize the disks to be added with pvcreate, and then extend the volume group with

vgextend.

Step 2 remains the same. Logical volumes are prepared for the new disks in the same way.

See Using Serviceguard Extension for RAC, June 2007 at http://docs.hp.com/en/ha.html → Serviceguard Extension for Real Application

Cluster (Serviceguard OPS Edition).