Monitoring Message Store Partitions

You can halt messages from being delivered to a message store partition when the partition fills more than a specified percentage of available disk space. This is done by setting two configutil parameters to enable the feature and specify the disk-usage threshold.

With this feature, the message store daemon monitors the partition’s disk usage. As disk usage increases, the store daemon dynamically checks the partition more frequently (ranging from once every 100 minutes to once a minute).

If disk usage goes higher than the specified threshold, the store daemon:

• Locks the partition. Incoming messages are held in the MTA message queue, but not delivered to the mailboxes in the message store partition.

• Logs a message to the default log file.

• Sends an email notification to the postmaster. (You can change the recipient of the email by setting the configutil parameter alarm.msgalarmnoticercpt.)

When disk usage falls below the threshold, the partition is unlocked, and messages are again delivered to the store.

The configutil parameters are as follows:

• local.store.checkdiskusage enables the partition-monitoring feature.

  Allowable values: yes, no

  Default value: yes

• local.store.diskusagethreshold specifies the disk-usage threshold. The value of local.store.diskusagethreshold is a percentage from 1 to 99.

  Default value: 99

You should set the disk-usage threshold to a percentage low enough to give you time to repartition or assign more disk space to the local message store.

For example, suppose a partition fills up disk space at a rate of 2 percent per hour, and it takes an hour to allocate additional disk space for the local message store. In this case, you should set the disk-usage threshold to a value lower than 98 percent.