SparseCat
Goal
Transmitting sparse files using minimal amount of network bandwidth. Sparsecat uses the SEEK_HOLE and SEEK_DATA capabilities of unix filesystems to find holes in sparse files and only transmits sections containing data. The wire format is simple and compatible with the ceph rbd diff v1 format as described here
Support
Because the tool relies on the lseek syscall with SEEK_HOLE and SEEK_DATA
only unix systems with the correct filesystems are supported. See the man pages
for more information. sparsecat does work with unsupported filesystems, but it
will simply transmit the entire file with a couple of bytes of overhead.