Abstract: A method for generating a crash-consistent backup of a source volume includes designating certain blocks of an operating source volume to be copied to a target volume, copying the designated blocks from the source volume to the target volume; initiating a time-based tracking process and detecting writes to blocks of the source volume. Using the time-based tracking process to maintain a time-ordered list of blocks that are written to during the copying of blocks to the target volume and to determine when the blocks on the target volume are in a sane state that permits a crash-consistent backup. After the designated blocks are copied, using the time-ordered list to continue copying blocks to the target volume. After the time-tracking process determines the blocks on the target volume are crash consistent (i.e., in a sane state), a snapshot can be transferred to a backup volume and time-tagged as a crash-consistent backup.