When a storage device is malfunctioning, you can avoid permanent device loss (PDL) conditions or all paths down (APD) conditions and perform a planned removal and reconnection of a storage device.
Planned device removal is an intentional disconnection of a storage device. You might also plan to remove a device for such reasons as upgrading your hardware or reconfiguring your storage devices. When you perform an orderly removal and reconnection of a storage device, you complete a number of tasks.
Migrate virtual machines from the device you plan to detach.
See the vCenter Server and Host Management documentation.
Unmount the datastore deployed on the device.
See Unmount Datastores.
Detach the storage device.
For an iSCSI device with a single LUN per target, delete the static target entry from each iSCSI HBA that has a path to the storage device.
Perform any necessary reconfiguration of the storage device by using the array console.
Reattach the storage device.
Mount the datastore and restart the virtual machines. See Mount Datastores.