A system and method for block-based restarts are described. A data storage system interfaces with one or more nodes of a network file system on which a volume is provided in order to read data stored on the volume on a block-by-block basis. Backup data sets capable of recreating the data on the volume are generated from the data blocks read from the volume. The system can interface with a backup memory resource and write the backup data sets to the backup memory resource in a sequential order. As the backup data sets are generated and written to the backup memory resource, restart checkpoints for the data set are also regularly generated and stored for use in restarting the backup process in the event of a recoverable failure in the transfer.