IBM DS8880 Series Introduction And Planning Manual page 94

cause a permanent encryption deadlock, which might result in the permanent loss
of all key-server-managed encrypted data at all of your installations.
The storage system automatically tests access to the encryption keys every 8 hours
and access to the key servers every 5 minutes. You can verify access to key servers
manually, initiate key retrieval, and monitor the status of attempts to access the
key server.
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DS8880 Introduction and Planning Guide