Managing throttles for volumes

You can create, modify, and remove throttles for volumes by using the management GUI or the command-line interface.

Throttling is a mechanism to control the amount of resources that are used when the system is processing I/Os on a specific volume or volume group. If a throttle is defined, the system either processes the I/O, or delays the processing of the I/O to free resources for more critical I/O.

Managing throttles with the management GUI

To create a new throttle or edit an existing throttle for a specific volume, complete these steps:
  1. In the management GUI, select Volumes > Volumes.
  2. Right-click a volume and select Edit Throttle....
    Note: You can select multiple volumes to apply throttles to more than one volume.
  3. On the Edit Throttle page, enter values for the following throttles:
    Bandwidth Limit
    Enter the maximum amount of bandwidth the volume can process before the system delays the processing for this volume. Click Create.
    IOPS Limit
    Enter the maximum I/O operations per second the volume can process before the system delays the processing for this volume. Click Create.
To edit an existing throttle for a specific volume, complete these steps:
  1. In the management GUI, select Volumes > Volumes.
  2. Right-click a volume and select Edit Throttle....
  3. On the Edit Throttle page, enter values for the following throttles:
    Bandwidth Limit
    Enter the maximum amount of bandwidth the volume can process before the system delays the processing for this volume. Click Save.
    IOPS Limit
    Enter the maximum I/O operations per second the volume can process before the system delays the processing for this volume. Click Save.
To remove throttles for a specific volume, complete these steps:
  1. In the management GUI, select Volumes > Volumes.
  2. Right-click a volume or multiple volumes and select Edit Throttle....
  3. On the Edit Throttle page, click Remove by the throttle that you want to delete.

Managing throttles with the command-line interface

To create a new throttle or edit an existing throttle for a volume with the command-line interface, enter the following command:
mkthrottle -type vdisk -bandwidth bandwidth_limit_in_mb -iops iops_limit -vdisk  vdisk_id_or_vdisk_name 
where bandwidth_limit_in_mb is the maximum amount of bandwidth that the system can process for the specified volume before the system delays processing of I/O for that volume. The iops_limit is the maximum I/O operations per second that the system can process before the system delays the processing for this volume. The vdisk_id_or_vdisk_name is the ID or name of the volume that the throttle applies to.
To change an existing throttle for the volume, enter the following command:
chthrottle -type vdisk -bandwidth bandwidth_limit_in_mb -iops iops_limit throttle_name_or_id 
where bandwidth_limit_in_mb is the maximum amount of bandwidth that the system can process for the specified host before the system delays processing of I/O for that volume. The iops_limit is the maximum I/O operations per second that the system can process before the system delays the processing for this volume. The throttle_id_or_name is the ID or name of the throttle that is being changed.
To remove a throttle for volume with the command-line interface, enter the following command:
rmthrottle throttle_name_or_id 
where throttle_name_or_id is the ID or name of the throttle that is being removed.