Automated resolution of configuration conflicts in a clustered environment.
Original Publication Date: 2002-Nov-02
Included in the Prior Art Database: 2003-Jun-21
Automated Resolution of Configuration Conflicts in a Clustered Environment. Disclosed is a method to automate the resolution of configuration conflicts that can occur in a clustered environment. This design uses a Configuration On Disk (COD) manager to process the configuration information stored on the disks and resolve any conflicts that are detected. The complexity of configurations can increase significantly in a clustered environment. System drives can be private (accessible by only one controller) or shared (accessible by all controllers in the cluster). When a clustered configuration is created or expanded using existing controllers and/or system drives, the configuration may have conflicts that need to be resolved. For example, two system drives may have the same system drive number. The COD manager in each controller shares configuration information (maps) to resolve configuration conflicts during boot up. This design provides a “plug and play” capability to the configuration of clustered systems and greatly minimizes any required customer intervention. At boot up time, the COD manager dynamically builds a System Drive Used Map to determine which system drives are in use across all the nodes in the Cluster (both Private and Public). This map is a bitmap where a value of 1 indicates the system drive number is in use by some node and a 0 indicates it is not in use. The first node to boot up becomes the master node. The COD manager of the master node treats the system configuration as a standalone configuration. This means the master node only needs to resolve conflicts caused by system drives that are not native to this controller. A non-native or foreign system drive is a system drive that was created on another controller and then physically moved to another controller. The master node reads the COD data from a reserved area on each drive. The drive numbering of native drives takes precedence. If a conflict is detected between native and foreign system drives, the COD manager reassigns the system drive number of the foreign system drive.