HP Serviceguard manual Or --help, Or --version, Or --log-file, Or --log-level, Or --poll-interval

multi-node package to monitor identically-named root, boot, or swap volumes on cluster nodes. Because the root, boot, and swap volumes are critical to the functioning of the node , the service should be configured with service_fail_fast_enabled (page 244) set to yes.

When a monitored volume fails or becomes inaccessible, the monitor service will exit, causing the package to fail on the current node. The package’s failure behavior depends on its configured settings. For prompt recovery, HP recommends setting the value of service_restart (page 244) for the monitoring service to none.

To ensure that a package requiring a storage volume does not attempt to start on or fail over to a node where the storage volume is unavailable, the monitor service may be configured in a separate package, and a package dependency may be used to ensure that the required package is running, indicating the storage is available. Depending on the configuration, the monitor package could be a multi-node or failover package, and would be required to be running by the storage volume-dependent application package. Alternatively, if you are using EMS, please be aware that EMS resource dependencies operate in this fashion – a package will not be run unless the specified EMS resources conditions are met.

NOTE: When using the volume monitor to monitor LVM logical volumes, you need to make sure that the logical volume timeout value is properly configured. This value should be configured to be at least one second less than the poll-intervalspecified in the monitor service command. I/O requests to logical volumes with no timeout set may block indefinitely. See “Setting Logical Volume Timeouts” (page 180) for more information.

Command Syntax

The syntax for the monitoring command, cmvolmond, is as follows:

cmvolmond [-h, --help] [-v, --version] [-O, --log-file <log_file>

[-D, --log-level <1-7>

[-t, --poll-interval <seconds> <volume_path> [<volume_path> ...]

A brief description of each parameter follows:

-h or --help

Displays the usage, as listed above, and exits.

NOTE: Do not include the help or version parameters in your service command; this will result in immediate package failure at runtime.

-v or --version

Displays the monitor version and exits.

-O or --log-file

Specifies a file for logging (log messages are printed to the console by default).

-D or --log-level

Specifies the log level. The level of detail logged is directly proportional to the numerical value of the log level. That is, a log level of 7 will provide the greatest amount of log information. The default log level is 0.

-t or --poll-interval

Specifies the interval between volume probes. You can specify a polling interval of as little as 1 (one second), but bear in mind that a short polling interval (less than 10 seconds) may impair system performance if you are monitoring a large number of volumes. HP recommends a polling interval of at least 10 seconds if 50 or more volumes are being monitored by a single service command. The default polling interval is 60 seconds. In the event of a failed read attempt on a storage volume, the monitor service will terminate after a single poll interval. If a read attempt

Package Configuration Planning 129