Switching priority of an SPM group

All host bus adapters in one SPM group must have the same priority. Prioritized WWNs and non-prioritized WWNs cannot be mixed in one SPM group.

You can use an SPM group to switch priority of multiple HBAs from prioritized to non-prioritized, or vice versa. You can perform the upper-limit value control for the group by setting the upper-limit value on the group.

The upper-limit value of each HBA which belongs to the group is the upper-limit value set for the group divided by the number of HBAs which belong to the group and have I/O. The I/O existence in HBA is distinguished with one minute interval monitoring. The upper-limit value of HBAs which belong to the group is updated in one minute intervals. Therefore, when the existence of I/O is alternated, the upper-limit value of the group might be over or under the setting value.

For example, in the condition that the upper-limit value is set to 200 IOPS for group to which 2 HBAs belong and only 1 HBA has I/O, the upper-limit value allocated to each HBA is 200 (200÷1) IOPS. After that, if the number of HBAs that have I/O turns from 1 to 2, until the next detection (updating the HBA upper-limit value which belongs to the group is in one minute interval), the upper-limit value might become 400 (200+200) IOPS because the upper-limit value is allocated to 200 IOPS to each HBA, which is over the setting value for the group.

In the condition that the upper-limit value is set to 200 IOPS for group to which 2 HBAs belong and 2 HBAs have I/O, the upper-limit value allocated to each HBA is 100 (200÷2) IOPS. After that, if the number of HBAs which have I/O turns from 2 to 1, until the next detection (updating HBA upper-limit value which belongs to the group is in one minute interval), the upper-limit value might become 100 IOPS because the upper-limit value is allocated 100 IOPS to each HBA, which is under the setting value for the group.

Prerequisites

Required role: Storage Administrator (System Resource Management)

The Device Manager - Storage Navigator secondary window must be enabled.

Procedure

Display the Performance Monitor window.

In Device Manager - Storage Navigator:

Select Analytics in Explorer.

Select Performance Monitor in the tree to open the Performance Monitor window.

In Command Suite:

Select the Resources tab, and expand the Storage Systems tree.

Right-click the target storage system and then select Performance Monitor.

In the Performance Monitor window, click Server Priority Manager to open the Server Priority Manager window.

Click to change to Modify mode.

In the Server Priority Manager window, click Server Priority Manager. The Server Priority Manager main window appears.

Select the WWN tab.

In the lower-left tree, select and right-click an SPM group ().

Do one of the following:

To switch priority from prioritized to non-prioritized, select Prio ->> Non-Prio from the pop-up menu.

To switch priority from non-prioritized to prioritized, select Non-Prio ->> Prio from the pop-up menu.

Click Apply to apply the settings to the storage system.