Version 2.21
virtnbdbackup: Detect dirty regions containing only zeroes during
incremental backup (fstrim) (#250)
Before, any dirty block being part of the incremental/differential bitmap
would be backed up, even if not required. Thanks to the input and
enhancements by
Roman Grigoriev (grigoriev177 at gmail.com) and
Denis V. Lunev (den at openvz.org)
the zeroed block regions are now compared to the base:allocation
bitmap and detected as such.
This reduces the amount of data backed up if virtual machines have disks
configured with discard=unmap option and use fstrim to free unused space.
Full Changelog: v2.20...v2.21