Clonezilla [1] is a free, open source partition and disk imaging/cloning program similar to Acronis True Image®. It saves and restores only used blocks in hard drive. The file systems supported by Clonezilla are:
(1) ext2, ext3, ext4, reiserfs, reiser4, xfs, jfs of GNU/Linux
(2) FAT, NTFS of MS Windows
(3) HFS+ of Mac OS
(4) UFS2 of BSD
(5) VMFS3 and VMFS5 of VMware ESX
(6) Minix of Minix
Therefore you can image or clone GNU/Linux, MS windows, Intel-based Mac OS, FreeBSD/NetBSD/OpenBSD, VMware ESX, ChromiumOS/ChromeOS and Minix. LVM2 and hardware RAID device is supported, too. Two types of Clonezilla are available, Clonezilla live and Clonezilla SE (Server Edition). Clonezilla live is suitable for single machine backup and restore. While Clonezilla SE is for massive deployment, it can restore many computers simultaneously. Clonezilla is not only for a newbie system administrator, but also for a veteran. This BoF is intended for system administrators at LinuxFest Northwest 2015 to meet and discuss any ideas and issues about Clonezilla they might have.

[1] http://clonezilla.org