7.10.1 Adding hosts
This subsection explains how to add hosts to a hot-standby configuration depending on the number of hosts after addition of hosts.
There is a limit to the number of hosts that can run concurrently in a single system. Before you add a host, make sure that the added host will not exceed the maximum permitted number of hosts, which is 32 by default. However, if you use HA Monitor Extension, you can increase the maximum number.
- Organization of this subsection
(1) When the number of hosts after addition will not exceed 32
This subsection explains how to add hosts when the number of hosts after addition will not exceed 32. You must install HA Monitor on a host that is to be added. For details about the configuration procedure after HA Monitor installation, see 6.1 Configuration procedure. This subsection explains only the differences when hosts are added from when the entire system is newly configured.
-
Configuring the monitoring paths
When you add a new host, you must change the HA Monitor connection configuration file. The names of all connected hosts are specified in the HA Monitor connection configuration file.
If you create the HA Monitor connection configuration files automatically, start the HA Monitors on all hosts. HA Monitor connection configuration files will be created automatically.
If you create the HA Monitor connection configuration files manually, edit the file and then make sure that the contents of the files on all hosts are the same.
For details about how to create an HA Monitor connection configuration file, see 6.10.2 Creating an HA Monitor connection configuration file.
(2) When the number of hosts after addition will be 33 or more
This subsection explains how to add hosts when the number of hosts after addition will be 33 or more. If you use HA Monitor Extension, you can set the maximum number of hosts to 33 or more. For details about increasing the maximum number of hosts by using HA Monitor Extension, see 3.7.2 Changing the maximum number of hosts.
This subsection explains how to add hosts up to the maximum number (upper limit) specified during configuration and beyond that maximum number.
(a) Adding hosts within the range of the maximum value
To add hosts up to the maximum value specified during configuration, perform all steps shown in the figure in (2) System configuration procedure (when using HA Monitor Extension).
For details about the Configure the monitoring paths step shown in Figure 6-1, see (1) When the number of hosts after addition will not exceed 32.
(b) Changing the maximum value
To change the upper limit specified during configuration:
-
Terminate all servers running on all hosts in the hot-standby configuration.
To ensure that all servers have terminated, execute the server and host status display command (monshow command) and check that all the servers on that host have terminated.
-
Terminate all HA Monitors on all hosts in the hot-standby configuration.
To ensure that the HA Monitors have terminated, check syslog for the KAMN050-I messages issued for the HA Monitors on both hosts.
-
Specify the settings required for adding hosts on all hosts in the hot-standby configuration.
Perform all steps shown in the figure in (2) System configuration procedure (when using HA Monitor Extension).
For details about the Configure the monitoring paths step shown in Figure 6-1, see (1) When the number of hosts after addition will not exceed 32.
To perform the Create definition files (HA Monitor) step shown in Figure 6-1, modify the hostmax operand in the definition file used to set up a HA Monitor operating environment. For details about the hostmax operand, see 8.3.1 HA Monitor environment settings (sysdef).