Article Number: 000194291
PowerStore: How to change volume node affinity
Summary: This KB provides guidance on how to change volume node affinity.
Article Content
Instructions
Node affinity defines the node which offers optimized I/O for a volume.
Dynamic Node Affinity for volumes was introduced with PowerStoreOS v2.1. This allows the PowerStore to automatically change Node Affinity of a volume based on the performance of the system.
Attention: Setting a volume manually to Preferred_Node_A/B prevents the PowerStore from changing the Node Affinity based on system performance.
Volume node affinity should only be changed manually if recommended by Dell Technical Support or Engineering. Changing this setting randomly can result in poor performance.
This cannot be changed in the PowerStore Manager user interface, but can be changed using the PowerStore CLI (PSTCLI).
Possible affinity values for a volume are shown in this list. Only the values that are shown in bold can be set manually with PSTCLI.
If a volume has Preferred_Node_A/B set, and you want the system to manage the Node affinity again, set the volume System_Select_At_Attach.
If the volume has active Host mappings, it automatically changes to either System_Selected_Node_A or System_Selected_Node_B.
Dynamic Node Affinity for volumes was introduced with PowerStoreOS v2.1. This allows the PowerStore to automatically change Node Affinity of a volume based on the performance of the system.
Attention: Setting a volume manually to Preferred_Node_A/B prevents the PowerStore from changing the Node Affinity based on system performance.
Volume node affinity should only be changed manually if recommended by Dell Technical Support or Engineering. Changing this setting randomly can result in poor performance.
This cannot be changed in the PowerStore Manager user interface, but can be changed using the PowerStore CLI (PSTCLI).
Checking current node affinity settings
Using the PowerStore Manager user interface
To see the current settings, check the PowerStore Manager user interface, under Storage > Volumes.
If you cannot see the node affinity column in the Volumes table, add it using the Show/Hide Table Columns:
Or to list only one volume:
The fields that are shown in green must be changed to match your information.
If you cannot see the node affinity column in the Volumes table, add it using the Show/Hide Table Columns:
Using the PowerStore CLI (PSTCLI)
To list all volumes:
pstcli -d cluster_ip -u admin -p admin_password volume show -select name,node_affinity
|
Or to list only one volume:
pstcli -d cluster_ip -u admin -p admin_password volume -name your_volume show
|
Changing node affinity
Using the PowerStore CLI (PSTCLI)
To change node affinity:pstcli -d cluster_ip -u admin -p admin_password volume -name your_volume set -node_affinity Preferred_Node_X |
Possible affinity values for a volume are shown in this list. Only the values that are shown in bold can be set manually with PSTCLI.
| System_Select_At_Attach | Affinity is assigned when the volume is first attached. | Can be manually set |
| System_Selected_Node_A | System selected Node A as the optimized I/O path to volume. | Reserved for system use |
| System_Selected_Node_B | System selected Node B as the optimized I/O path to volume. | Reserved for system use |
| Preferred_Node_A | Node A is set as the optimized I/O path to volume. | Can be manually set |
| Preferred_Node_B | Node B is set as the optimized I/O path to volume. | Can be manually set |
If a volume has Preferred_Node_A/B set, and you want the system to manage the Node affinity again, set the volume System_Select_At_Attach.
If the volume has active Host mappings, it automatically changes to either System_Selected_Node_A or System_Selected_Node_B.
Article Properties
Affected Product
PowerStore, PowerStore 1000X, PowerStore 1000T, PowerStore 3000X, PowerStore 3000T, PowerStore 5000X, PowerStore 5000T, PowerStore 500T, PowerStore 7000X, PowerStore 7000T
Product
PowerStore Expansion Enclosure, PowerStore Rack, PowerStore 9000X, PowerStore 9000T
Last Published Date
12 Apr 2023
Version
7
Article Type
How To