HBase incremental backups enable more efficient capture of HBase table images than previous attempts at serial backup-and-restore solutions, such as those that only used HBase Export and Import APIs. Incremental backups use Write Ahead Logs (WALs) to capture the data changes since the previous backup was created. A roll log is executed across all RegionServers to track the WALs that need to be in the backup.
After the incremental backup image is created, the source backup files usually are on same node as the data source. A process similar to the DistCp (distributed copy) tool is used to move the source backup files to the target filesystems. When a table restore operation starts, a two-step process is initiated. First, the full backup is restored from the full backup image. Second, all WAL files from incremental backups between the last full backup and the incremental backup being restored are converted to HFiles, which the HBase Bulk Load utility automatically imports as restored data in the table.
You can only restore on a live HBase cluster because the data must be redistributed to complete the restore operation successfully.