Managing Serviceguard Eighteenth Edition, September 2010

3. Verify that a local switch has taken place so that the Standby card is now the
Primary card. In Serviceguard Manager, check the cluster properties. On the
command line, use cmviewcl -v.
4. Reconnect the LAN to the original Primary card, and verify its status. In
Serviceguard Manager, check the cluster properties. On the command line, use
cmviewcl -v.
Monitoring Hardware
Good standard practice in handling a high availability system includes careful fault
monitoring so as to prevent failures if possible or at least to react to them swiftly when
they occur. The following should be monitored for errors or warnings of all kinds:
• Disks
• CPUs
• Memory
• LAN cards
• Power sources
• All cables
• Disk interface cards
Some monitoring can be done through simple physical inspection, but for the most
comprehensive monitoring, you should examine the system log file (/var/adm/
syslog/syslog.log) periodically for reports on all configured HA devices. The
presence of errors relating to a device will show the need for maintenance.
When the proper redundancy has been configured, failures can occur with no external
symptoms. Proper monitoring is important. For example, if a Fibre Channel switch in
a redundant mass storage configuration fails, LVM will automatically fail over to the
alternate path through another Fibre Channel switch. Without monitoring, however,
you may not know that the failure has occurred, since the applications are still running
normally. But at this point, there is no redundant path if another failover occurs, so the
mass storage configuration is vulnerable.
Using Event Monitoring Service
Event Monitoring Service (EMS) allows you to configure monitors of specific devices
and system resources. You can direct alerts to an administrative workstation where
operators can be notified of further action in case of a problem. For example, you could
configure a disk monitor to report when a mirror was lost from a mirrored volume
group being used in the cluster.
See the manual Using High Availability Monitors at the address given in the preface to
this manual.
Monitoring Hardware 401