Expanding DR Star LUNs

Prerequisites

To prevent adverse impact on host services, you are advised to perform capacity expansion when the CPU usage and disk usage of the storage systems are lower than 50%.

To query the CPU usage and disk usage, log in to DeviceManager and choose Insight > Performance > Analysis.

• CPU usage: Create a chart. Set Object Type to Controller and select Avg. CPU Usage (%) in Statistical Metric.
• Disk usage: Create a chart. Set Object Type to Disk and select Usage (%) in Statistical Metric.

Context

• If you expand LUNs on the storage system where a DR Star trio is created, the LUNs on the other two storage systems will be automatically expanded. If you expand LUNs on either of the other two storage systems, only the local LUNs will be expanded.
• The capacities of all the LUNs in the DR Star trio must be the same after expansion.
• When you perform capacity expansion on DeviceManager, the system automatically checks Running Status of the HyperMetro pair and remote replication pair. If Running Status is not Paused for the HyperMetro pair or Split for the remote replication pair, the system pauses the HyperMetro pair or splits the remote replication pair before performing capacity expansion.

Procedure

1. Log in to DeviceManager of the storage system where the DR Star trio is created.
2. Choose Services > LUNs.
3. Click on the right of the LUN to be expanded and select Expand from the drop-down list.

   The Expand LUN page is displayed on the right.

4. Set Added Capacity to the amount of capacity that you want to add and select a unit.
5. Select or deselect Only expand the local LUN and Start data sync after expansion.
   • If you do not select Only expand the local LUN, the system will expand all LUNs in the DR Star trio. If you select Only expand the local LUN, the system will expand only the local LUNs. In this case, manually expand other LUNs. During capacity expansion, HyperMetro services will be suspended and remote replication services will be split. Select Start data sync after expansion or manually start synchronization.
   • You are advised to select Only expand the local LUN in the following scenarios:
     • The links to the remote devices are disconnected.
     • The capacities of the local and remote LUNs are different.

6. Click OK.
7. In the Danger dialog box, confirm the expansion information, select I have read and understand the consequences associated with performing this operation, and click OK.
8. Verify and use the added capacity.
   1. Click the LUN whose capacity has been expanded and view its current Capacity.

      If the Capacity value is the same as the actual capacity (the original capacity plus the added capacity), the capacity expansion is successful. Otherwise, rectify the fault based on the alarm information.

   2. After the capacity expansion is successful, log in to the application server as the system administrator and scan for disks again. After the scanning is successful, the newly added storage capacity is available to the application server.

9. (Optional) Manually synchronize the HyperMetro pair and remote replication pair.

   Skip this step if you have selected Start data sync after expansion.