HP Serviceguard Extension for RAC (SGeRAC) manual # mkdir /dev/vgrac, # ls -l /dev/*/group

Creating a Volume Group with PVG-Strict Mirroring

Use the following steps to build a volume group on the configuration node (ftsys9). Later, the same volume group will be created on other nodes.

1.Set up the group directory for vgops:

#mkdir /dev/vg_rac

2.Create a control file named group in the directory /dev/vg_rac, as follows:

#mknod /dev/vg_rac/group c 64 0xhh0000

The major number is always 64, and the hexadecimal minor number has the form

0xhh0000

where hh must be unique to the volume group you are creating. Use the next hexadecimal number that is available on your system, after the volume groups that are already configured. Use the following command to display a list of existing volume groups:

#ls -l /dev/*/group

3.Create the volume group and add physical volumes to it with the following commands:

#vgcreate -g bus0 /dev/vg_rac /dev/dsk/c1t2d0

#vgextend -g bus1 /dev/vg_rac /dev/dsk/c0t2d0

The first command creates the volume group and adds a physical volume to it in a physical volume group called bus0. The second command adds the second drive to the volume group, locating it in a different physical volume group named bus1. The use of physical volume groups allows the use of PVG-strict mirroring of disks and PV links.

4.Repeat this procedure for additional volume groups.

Building Mirrored Logical Volumes for RAC with LVM Commands

After you create volume groups and define physical volumes for use in them, you define mirrored logical volumes for data, logs, and control files. It is recommended that you use a shell script to issue the commands described in the next sections. The commands you use for creating logical volumes vary slightly depending on whether you are creating logical volumes for RAC redo log files or for use with Oracle data.

Creating Mirrored Logical Volumes for RAC Redo Logs and Control Files

Create logical volumes for use as redo log and control files by selecting mirror consistency recovery. Use the same options as in the following example:

# lvcreate -m 1 -M n -c y -s g -n redo1.log -L 408 /dev/vg_rac

•-m1—Specifies single mirroring.

•-Mn—Ensures that mirror write cache recovery is set off.

•-cy—Mirror consistency recovery is enabled.

•-sg—Mirroring is PVG-strict. It occurs between different physical volume groups.

•-nredo1.log—Specify the name of the logical volume.

•-L28—allocates 28 megabytes.

NOTE: Use the -c y options for both redo logs and control files. These options allow the redo log files to be resynchronized by SLVM following a system crash before Oracle recovery proceeds. If these options are not set correctly, you may not be able to continue with database recovery.

If the command is successful, the system will display messages like the following:

42 Serviceguard Configuration for Oracle 10g, 11gR1, or 11gR2 RAC