6.23.1 Checking the settings and definitions between multiple hot-standby configurations

Regardless of the OS being used, if a system contains multiple hot-standby configurations in a network in which the same reset path is used and there is any duplication of address operand values in the HA Monitor environment settings or duplication of port numbers specified for HA Monitor's reset path, the following events might occur between the hot-standby configurations:

• In the event of a host failure, a host containing a hot-standby configuration that has nothing to do with that host failure might also result in a failure.

• When a host is rebooted, another host containing a hot-standby configuration that has nothing to do with the rebooted host might result in a failure.

To prevent these events in a system that contains multiple hot-standby configurations, you must check for duplications in the address operand values and the port numbers specified for HA Monitor's reset path. You can use the IP address detection command (monlistip command) to list the devices in the network that use the same reset path. For details about the IP address detection command (monlistip command), see 9.13 monlistip (detects IP addresses) in 9. Commands.

The following figure shows the procedure for checking the settings and definitions between multiple hot-standby configurations.

Figure 6‒64: Procedure for checking the settings and definitions between multiple hot-standby configurations

The following provides the details of the checking procedure, where the item numbers correspond to the step numbers in the figure.

To check settings and definitions:

1. List the devices in the reset path's network.

   You can use either of the methods described below. Make sure that all devices are listed.

   • Execute the IP address detection command (monlistip command).

     Execute this command from one of the hosts. The execution results are output to a CSV file. If you load this file on a computer running a Windows OS, you can edit it with a spreadsheet program. You can use the obtained results as the input in the steps that follow.

   • Contact the network administrator.

2. Check if HA Monitor can be applied to the devices.

   Check the system and OS of each device listed in step 1 to determine whether the devices might be using HA Monitor. For the systems that support HA Monitor, see Release Notes. The OSs that support HA Monitor include AIX, HP-UX, and Linux. The following example shows how to check the OS:

   • Determine from the prompt that is displayed when you log in with telnet.

   • Execute the uname command in remote shell (rsh), and then determine from the result.

3. Check whether the devices are using HA Monitor.

   For the devices that were determined in step 2 to have the possibility of using HA Monitor, check if they have an HA Monitor directory to determine whether they are actually using HA Monitor. Log in to each computer checked in step 2 and execute the following command:

   ls /opt/hitachi/HAmon

   If the four directories bin, etc, lib, and spool are found, you can conclude that the device is using HA Monitor.

4. Check the address operand values in the HA Monitor environment settings for all devices that are using HA Monitor.

   Check the address operand values for any duplications in the HA Monitor that is used by multiple devices.

   If an address operand value is duplicated, go to step 5. If none of the address operand values is duplicated, the check is now complete.

5. Execute the HA Monitor environment setup command (monsetup command) on all devices that are using HA Monitor to check the reset path settings.

   In the HA Monitor environment setup command (monsetup command), specify the -tty option (if the OS is AIX) or -resetpath option (if the OS is HP-UX or Linux) to check the reset path settings.

   The check items are as follows:

   • Port number of reset path

   • Port number of SVP or hot-standby mechanism at the connection destination

   • Port number of alternate reset path

   • Port number of alternate switchover mechanism at the connection destination

6. Check the port numbers for any duplications.

   For each of the hosts that contains a duplicated address operand value (as checked in step 4), if there are duplications in any of the items checked in step 5, go to step 7. If there are no duplications, checking is now completed.

7. Correct the duplicated port numbers.

   Separate the networks so that hosts using duplicated port numbers cannot communicate with each other.

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