Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Building a Metropolitan Cluster Using MetroCluster/SRDF
Setting up 1 by 1 Configurations
Chapter 4 157
1. Import the VGs on all of the other systems that might run the
MC/ServiceGuard package and backup the LVM configuration. Make
sure that you split the logical SRDF links before importing the VGs,
especially if you are importing the VGs on the R2 side. Use the
commands:
# symrdf -g devgrpname split -v
# vgimport -v -s -m mapfilename vgname
2. Back up the configuration. Use the following commands:
# vgchange -a y vgname
# vgcfgbackup vgname
# vgchange -a n vgname
# symrdf -g devgrpname establish -v
See the sample script Samples/mk2imports.
NOTE Exclusive activation must be used for all volume groups associated with
packages that use the EMC. The design of MetroCluster/SRDF assumes
that only one system in the cluster will have a VG activated at a time.
Configuring PV Links
The examples in the previous sections show the use of the vgimport and
vgexport commands with the -s option. Also, the mk1VGs script uses a -s
in the vgexport command, and the mk2imports script uses a -s in the
vgimport command. You may wish to remove this option from both
commands if you are using PV links. The -s option to the vgexport
command saves the volume group id (VGID) in the map file, but it does
not preserve the order of PV links. To specify the exact order of PV links,
do not use the -s option with vgexport, and in the vgimport command,
enter the individual links in the desired order, as in the following
example:
# vgimport -v -m mapfilename vgname linkname1 linkname2