Casync

casync
Original author	Lennart Poettering
Initial release	June 20, 2017 (2017-06-20)
Stable release	21  / 26 July 2017 (26 July 2017)
Written in	C
Operating system	Linux
Type	Data transfer
License	LGPLv2.1
Website	github.com/systemd/casync/
Repository	github.com/systemd/casync/

casync (content-addressable synchronisation) is a Linux software utility designed to distribute frequently-updated file system images over the Internet.²³

According to the creator Lennart Poettering, casync is inspired by rsync and Git,⁴ as well as tar.⁵ casync is aimed to be used for Internet of things (IoT), containerization, virtual machines (VMs), portable services, and operating system (OS) images, as well as backups and home directory synchronization.³ casync splits images into variable size segments, uses sha256 checksums, and aims to work with content delivery networks (CDNs).⁵⁴ Available for Linux only,⁴ packages are available for Ubuntu, Fedora and Arch Linux.⁵

Similar software that delivers file system images are:⁴

• Docker with a layered tarballs
• OSTree