Configuring the Disk Space Balancer

The disk space balancer checks every storage pool on a regular basis and moves containers from a storage pool when that pool's utilization meets the following conditions:

  • The storage pool is over 70% full.
  • The storage pool's utilization exceeds the average utilization on the cluster by a specified threshold:
    • When the average cluster storage utilization is below 80%, the threshold is 10%.
    • When the average cluster storage utilization is below 90% but over 80%, the threshold is 3%.
    • When the average cluster storage utilization is below 94% but over 90%, the threshold is 2%.

You can use the config save command to modify disk space balancer parameter values.

Example: # maprcli config save -values {"cldb.balancer.disk.max.switches.in.nodes.percentage":"20"}

The following table lists the disk space balancer configuration parameters with their default values and descriptions:
Parameter Value Description
cldb.balancer.disk.threshold.percentage 70 Threshold for moving containers out of a given storage pool, expressed as utilization percentage.
cldb.balancer.disk.paused 1

Specifies whether the disk space balancer runs:

  • 0 - Not paused (normal operation)
  • 1 - Paused (does not perform any container moves)
cldb.balancer.disk.max.switches.in.nodes.percentage 10 This can be used to throttle the disk balancer. If it is set to 10, the balancer will throttle the number of concurrent container moves (minimum 1) to 10% of the total nodes in the cluster rounded up.

You can view the disk usage of all the nodes in a cluster from the Disks view in the MCS. In the Navigation pane of the MCS, click Cluster > Nodes and then select Disks from the dropdown.