Managing the throttle for offload I/O

You can create, modify, and remove the offload I/O throttle 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. 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. The system also supports throttles to delay processing of I/O operations for offload I/O operations.

Using the management GUI

To create a new throttle for offload I/O, complete these steps:

In the management GUI, select System > Actions > Edit Offload I/O Throttle.
On the Edit Throttle page, enter values for the following throttles:
Bandwidth Limit

Enter the maximum amount of bandwidth the system can process before the system delays I/O processing for this offload. Click Create.

IOPS Limit

Enter the maximum I/O operations per second the system can process before the system delays I/O processing for this offload. Click Create.

To edit an existing throttle for offload I/O, complete these steps:

In the management GUI, select System > Actions > Edit Offload I/O Throttle.
On the Edit Throttle page, enter values for the following throttles:
Bandwidth Limit

Enter the maximum amount of bandwidth the system can process before the system delays I/O processing for this offload. Click Save.

IOPS Limit

Enter the maximum I/O operations per second the system can process before the system delays I/O processing for this offload. Click Save.

To remove the offload I/O throttle, complete these steps:

In the management GUI, select System > Actions > Edit Offload I/O Throttle.
On the Edit Throttle page, click Remove by the throttle that you want to delete.

Using the command-line interface

To create a new throttle for bandwidth and IOPS for offload I/O with the command-line interface, enter the following command:

mkthrottle -type offload -bandwidth bandwidth_limit_in_mb -iops iops_limit

where bandwidth_limit_in_mb is the maximum amount of bandwidth that the system can process for the specified offload before the system delays processing of I/O for that offload. The iops_limit is the maximum I/O operations per second that the system can process before the system delays I/O processing for this offload.

To change an existing throttle for offload I/O with the command line interface, enter the following command:

chthrottle -type offload -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 offload before the system delays I/O processing of I/O for that offload. The iops_limit is the maximum I/O operations per second that the system can process before the system delays I/O processing for this offload. The throttle_id_or_name is the ID or name of the throttle that is being changed.

To remove a throttle for an offload 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.