Configuring disk space monitor

To prevent problems that can occur if the disk partition containing the datastore files or log files runs out of space, the free disk space monitor is used. The monitor service uses the following predefined thresholds for disk space:

• Free disk space baseline threshold—The threshold below which the machine baseline raises a critical warning. By default, it is 2048 MB for the partition holding the datastore and 200MB for the partition holding the log files. Baseline threshold is twice of the free disk space threshold. The baseline threshold only raises a warning and does not shut down the machine or prevent it from starting.

• Free disk space shutdown threshold—The threshold below which the free disk space monitor gracefully shuts down BMC Discovery and prevents it from starting until the free disk space baseline threshold is available. By default, it is 1024 MB for the partition holding the datastore and 100Mb for the partition holding the log files.

  Note

  If free disk space on respective partitions on a machine in a cluster is below the shutdown threshold, the free disk space monitor shuts down all the machines on that cluster and prevents the machines from starting until the free disk space at least match the baseline threshold.

See the following video (3:51) to set up an email alert to monitor disk space on a Discovery appliance. 

https://youtu.be/DhTXW7uPRD4

For more information, see  How to avoid running out of disk space on a Discovery appliance  in BMC Communities.

Managing free disk space

You can perform the following operations related to managing and monitoring the disk space on a standalone machine or a cluster member:

• View the disk usage of a standalone machine
• View the disk usage of the cluster member

• Check the Appliance Disk Space

   
• Free up disk space on the machine
• Restart the services to recover from the forced shutdown

To view the disk usage of a standalone machine

1. From the main menu, click the Administration icon.  
   The Administration page opens.
2. In the Appliance section, click Disk Configuration.
   The Current Usage section of the Manage BMC Discovery Disks page displays the current disk usage. For more information, see Managing disks and swap space.
   

To view the disk usage of the cluster member

1. On the coordinator, click Administration.
2. In the Appliance section, click Cluster Management.
   The Cluster Management page displays the disk usage of each machine on the cluster.
   

To check the Appliance Disk Space against the baseline 

You check the Appliance Disk Space against the predefined baseline on a standalone machine or any cluster member.

1. From the main menu, click the Administration icon.  
   The Administration page opens.
2. In the Appliance section, click Baseline Status.
   The Baseline Status page displays the results of the recent checks.

3. Click Check Baseline Now at the bottom of the list to get the latest information and see if the Appliance Disk Space check status is OK.

    

Freeing up disk space

If the free disk space is below the baseline threshold, a critical baseline warning is raised.

To prevent shutdown, you must free up some disk space on the machine. Possible areas from which you might free up disk space are:

• Application log files—See Contents of the logs for a description and the location of the main application log files. BMC Discovery is not reliant on these log files and they can be safely deleted. However, the datastore transaction logs must not be deleted. For more information, see operational warnings.
• Cores—Check that there are no old cores in $TIDEWAY/cores.
• Record data—You can delete any record data that is not required, or using the disk configuration tool you can move record data to an additional disk.
• Workspaces—Any areas that you have used as workspaces or staging areas for exports.

If the free disk space is below the shutdown threshold, the free space monitor shuts the machine down and the UI displays the machine name which has insufficient free disk space. You must log on to that machine and free up the disk space to the baseline threshold at the minimum. Thereafter, you must restart the services.

To restart the services to recover from a forced shutdown

When the free disk space goes below the shutdown threshold which is equal to baseline threshold multiplied by two, the BMC Discovery services are stopped. After you free up the space on the machine that caused the shutdown, you need to restart these services.

To restart services, run the following command on a standalone machine or on any machine in the cluster:

tw_cluster_control --cluster-start-services