A method and system for backing up and restoring a data set on a node of a
distributed system prevents conflicts in data replication caused by
restoration from backup data. Before a node is backed up, state data of
the data set of the node are set to mark the data set as "backed up." The
data set also stores a lowest serial number for uncommitted changes. A
snapshot of the data set, including the state data, of the node is then
taken to provide a backup copy. When the backup copy is later used to
restore the data set of the node, the "backed up" value of the state data
of the restored data set serves as a notification to the replication
server of the node that the data set has been restored, so that the
replication server will switch to a new Node ID for labeling new changes
for replication to other nodes in the distributed system.