Expanding the Capacity of HyperMetro LUNs

Prerequisites

• The Running Status of the HyperMetro pair is Normal and the links are normal; or the Running Status of the HyperMetro pair is Paused.

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

  To query the CPU and disk usages, 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

• Both the primary and secondary LUNs must be expanded and their capacities must be the same after the expansion.
• Capacity expansion can be performed online without service interruption.
• When you perform capacity expansion on DeviceManager, the system checks whether the Running Status of the HyperMetro pair is Paused. If it is not Paused, the system prompts a message asking you to pause the service on a site.

Procedure

1. Log in to DeviceManager.
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 dialog box is displayed.

4. Set Added Capacity to the amount of capacity that you want to add and select a unit.
5. (Optional) 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 both the local and remote LUNs. If you select Only expand the local LUN, the system will only expand the local LUN. In this case, manually expand the remote LUN.
   • Select Only expand the local LUN in the following scenarios:
     • The Running Status of the HyperMetro pair is Paused and the replication link is disconnected.
     • The capacities of the local and remote LUNs are different.
     • The HyperMetro pair forms a cascading 3DC network with a remote replication pair.

6. Click OK.
7. In the security alert dialog box, confirm the added capacity and the paused site, 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.

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