Using Serviceguard Extension for RAC, 9th Edition, September 2010
NOTE: If you wish to change the capacity of a volume group at a later time, you must deactivate
and unshare the volume group first. If you add disks, you must specify the appropriate physical
volume group name and make sure the /etc/lvmpvg file is correctly updated on both nodes.
Making Offline Changes to Shared Volume Groups
You may need to change the volume group configuration of RAC shared logical volumes to add
capacity to the data files or to add log files. No configuration changes are allowed on shared
LVM volume groups while they are activated. The volume group must be deactivated first on
all nodes, and marked as non-shareable.
To learn more about an additional method, Single Node Online volume Re-Configuration (SNOR),
please see the white paper SLVM Online Volume Re-configuration at
www.hp.com/go/hpux-core-docs —> HP-UX 11i v3 —> White papers.
Use the following procedure (examples assume the volume group is being shared by node 1 and
node 2, and they use the volume group vg_ops):
1. Ensure that the Oracle RAC database is not active on either node.
2. From node 2, use the vgchange command to deactivate the volume group:
# vgchange -a n /dev/vg_ops
3. From node 2, use the vgexport command to export the volume group:
# vgexport -m /tmp/vg_ops.map.old /dev/vg_ops
This dissociates the volume group from node 2.
4. From node 1, use the vgchange command to deactivate the volume group:
# vgchange -a n /dev/vg_ops
5. Use the vgchange command to mark the volume group as unshareable:
# vgchange -S n -c n /dev/vg_ops
6. Prior to making configuration changes, activate the volume group in normal (non-shared)
mode:
# vgchange -a y /dev/vg_ops
7. Use normal LVM commands to make the needed changes. Be sure to set the raw logical
volume device file's owner to oracle and group to dba with a mode of 660.
8. Next, from node 1, deactivate the volume group:
# vgchange -a n /dev/vg_ops
9. Use the vgexport command with the options shown in the example to create a new map
file:
# vgexport -p -m /tmp/vg_ops.map /dev/vg_ops
Make a copy of /etc/lvmpvg in /tmp/lvmpvg, then copy the file to /tmp/lvmpvg on
node 2. Copy the file /tmp/vg_ops.map to node 2.
10. Use the following command to make the volume group shareable by the entire cluster again:
# vgchange -S y -c y /dev/vg_ops
11. On node 2, issue the following command:
# mkdir /dev/vg_ops
12. Create a control file named group in the directory /dev/vg_ops, as in the following:
# mknod /dev/vg_ops/group c 64 0xhh0000
The major number is always 64, and the hexadecimal minor number has the format:
0xhh0000
120 Maintenance and Troubleshooting