Building Disaster Tolerant Serviceguard Solutions Using Metrocluster with EMC SRDF
Some Further Points
Chapter 5 329
The Symmetrix device group name must be the same on each host for
both R1 side and R2 side. This group name is placed variable
DEVICE_GROUP defined in the pkg.env file.
Although the name of the device group must be the same on each
node, the special device file names specified may be different on each
node.
Symmetrix Logical Device names MUST be default names of the
form “DEVnnn” (for example, DEV001). Do not use the option for
creating your own device names.
See the EMC Solutions Enabler manual, and the sample convenience
scripts in the Samples directory included with this toolkit.
• To minimize contention, each device group used in the package
should be assigned two unique gatekeeper devices on the Symmetrix
for each host where the package will run. These gatekeeper devices
must be associated with the Symmetrix device groups for that
package. The gatekeeper devices are typically a 2 MB logical device
on the Symmetrix.
For example, if a package is configured to failover across four nodes
in the cluster, there should be eight gatekeeper devices (two for each
node) that are assigned to the Symmetrix device group belonging to
this package.
It is required that there be a pool of four additional gatekeeper
devices that are NOT associated with any device group. These
gatekeepers would be available for other, non-cluster uses, for
example, the Symmetrix Manager GUI and other EMC Solutions
Enabler or SymAPI requests.
After data configuration, each physical device in the Symmetrix has
enough space remaining on it for gatekeeper purposes.
• This toolkit does not support the HP OmniBack Integration with
Symmetrix. The OmniBack Integration with Symmetrix may create
certain states that will cause this package to halt if a failover occurs
while the backup is in progress.
• No checking of the status of the SA/FA ports is done. It is assumed
that at least one PVLink is functional. Otherwise, the VG activation
will fail.