550   A clustered system cannot be formed because of a lack of clustered system resources.

The node cannot become active because it is unable to connect to enough system resources. The system resources are the node in the system and the active quorum disk or drive. The node must be able to connect to most of the resources before that group forms an online system. This connection prevents the system from splitting into two or more active parts, with both parts independently performing I/O.

The error data lists the missing resources. This information includes a list of nodes and optionally a drive that is operating as the quorum drive or a LUN on an external storage system that is operating as the quorum disk.

If a drive in one of the system enclosures is the missing quorum disk, it is listed as enclosure:slot[part identification] where enclosure:slot is the location of the drive when the node shutdown, enclosure is the seven-digit product serial number of the enclosure, slot is a number 1 - 24. The part identification is the 22 character string that starts with "11S" found on a label on a drive. The part identification cannot be seen until the drive is removed from the enclosure.

If a LUN on an external storage system is the missing quorum disk, it is listed as WWWWWWWWWWWWWWWW/LL, where WWWWWWWWWWWWWWWW is a worldwide port name (WWPN) on the storage system that contains the missing quorum disk and LL is the Logical Unit Number (LUN).

If the system topology is stretched and the number of operational nodes is less than half, then node error 550 is displayed. In this case, the Site Disaster Recovery feature cannot be used as the number of operational nodes is less than the quorum required to create the system that uses the Site Disaster Recovery feature.