HP AD510A - StorageWorks Modular Smart Array 1500 cs 2U Fibre Channel SAN Attach Controller Shelf Hard Drive Installation Manual page 29

Note:
HP StorageWorks 1500 Modular Smart Array Installation Guide
If both controllers are operational and both need servicing, schedule a
maintenance window and perform the service as for a single-controller
configuration.
If both controllers are operational and one needs servicing, do the following to
disable and then service the controller:
The MSA operates in a non-redundant mode during this procedure.
a. Access a supported management utility for the MSA.
b. In the utility, disable the controller to be removed.
For details, see the utility online help or MSA user documentation.
c. Wait for array controller disabled to display on the controller
LCD panel.
d. Remove the disabled controller for servicing or replacement.
Caution: If an operational controller is removed without first being disabled,
the active controller might halt. To clear this fault condition, you must
power-cycle the MSA.
For more information, see the HP StorageWorks 1500 Modular Smart Array
Maintenance and Service Guide, available on the Technical documents page
of the MSA1500 website: http://www.hp.com/go/msa1500cs.
Installation Procedures - All Deployments
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