Heal-On-Rewrite for ext4-snapshots

by Yongqiang Yang for The Linux Foundation

NEXT3(R) is a flavor of the widely used Ext3 file system with built-in support for snapshots. Developed by CTERA Networks, NEXT3 is licensed under the GPL. It is being merged to ext4 now. Metadata blocks are snapshotted by copy-on-write while data blocks are are snapshotted by move-on-write. For more information, please refer to http://sourceforge.net/apps/mediawiki/next3/index.php?title=Ext4_snapshots_TODO