Insufficient Cache Backup Device Capacity

What Caused the Problem?

There is currently more cache memory capacity than cache backup device capacity. Therefore, the cached data cannot be backed up in the event of a power failure. The Recovery Guru Details area provides specific information you will need as you follow the recovery steps.

 Caution: Electrostatic charges can damage sensitive components. Always use proper antistatic protection when handling components. Touching components without using a proper ground may damage the equipment.

Important Notes

Recovery Steps

If... Then...
One of the following problems IS also reported in the Summary area:
  • Cache Backup Device Failed
  • Cache Backup Device in Write-Protect Mode"
Do not continue with these Recovery Steps. Complete the Recovery Steps for the other problem(s), which should also resolve this problem.
One of the following problems is NOT reported in the Summary area:
  • Cache Backup Device Failed
  • Cache Backup Device in Write-Protect Mode"
If... Then...
Your storage subsystem has one controller Go to "Procedure for Storage Subsystems with One Controller."
Your storage subsystem has two controllers Go to "Procedure for Storage Subsystems with Two Controllers."

Procedure for Storage Subsystems with One Controller

1 Stop all I/O from all hosts to this storage subsystem. When the Cache Active LED on the controller is no longer blinking (may take several minutes), proceed to step 2.

 Caution: Risk of Data Loss. You must wait for the Cache Active LED to stop blinking to ensure that all cache has been written to disk.

2 Click the Save As button in the Recovery Guru dialog to save the remaining steps to file. The remaining Recovery Steps will no longer be accessible from the Recovery Guru dialog after you complete step 3.
3 Remove the affected controller canister (listed in the Component requiring service field in the Details area).
4 Refer to the Enterprise Management Window (EMW) to view which management method you are using to manage this storage subsystem.
If... Then...
You are using In-Band management for ALL hosts attached to this storage subsystem Go to step 5.
You are using Out-of-Band management for ANY host attached to this storage subsystem Before you insert a new controller canister into the storage subsystem, you must update the DHCP/BOOTP server so that it will associate the new controller's hardware Ethernet (MAC) address with the DNS/network name and IP address previously assigned to the removed controller.

To update the DHCP/BOOTP server, find the entry associated with the removed controller and replace its Ethernet (MAC) address with the new controller's Ethernet (MAC) address. The controller's Ethernet (MAC) address is located on an Ethernet ID label on the controller canister in the form xx.xx.xx.xx.xx.xx.

When you are finished, go to step 5.

5 If the new controller canister does NOT contain a battery, insert the battery from the old controller canister into the new replacement controller canister. Consult your hardware documentation for details.
6 Insert the controller canister securely into place. After the controller appears in the Physical View of the AMW, go to step 7.

Note: Write caching will be reinstated (if applicable for each logical drive) once the controller's battery is fully charged and has completed any required learn cycles (if applicable).

7 Click the Recheck button to rerun the Recovery Guru. The failure should no longer appear in the Summary area. If the failure appears again, contact your technical support representative.

Procedure for Storage Subsystems with Two Controllers

1 If there are any hosts connected to this storage subsystem that are NOT running a host-based, multi-path failover driver, stop I/O to the storage subsystem from each of these hosts.
2 Place the affected controller offline. The affected controller is listed in the Component requiring service field in the Details area.
a Select the controller in the physical view of the Subsystem Management Window.
b Select Advanced >> Recovery >> Set Controller >> Offline.
c Complete the instructions in the dialog, then select Yes.
3 Read all of the following steps before taking any action. The remaining Recovery Steps will no longer be accessible from the Recovery Guru dialog after you complete step a.
a Click the Recheck button to rerun the Recovery Guru.
b Select the "Offline Controller" problem that is being reported in the Summary area.
c Complete the Recovery Steps in the "Offline Controller" recovery procedure to replace the affected controller.