3 ms·
Volume snapshots are a better way. The only filesystems I know of that support them are ZFS, BtrFS, and HAMMER. I'm not sure if snapshots are implemented using
by oofabz 13y ago
Volume snapshots are a better way. The only filesystems I know of that support them are ZFS, BtrFS, and HAMMER. I'm not sure if snapshots are implemented using hard links or if they are more fundamental.
Another way, which is worse, is block-level deduplication. All of the above filesystems support it, as does NTFS.
I wish Apple would adopt HAMMER for Mac OS. It is BSD-licensed and more suitable for a memory-constrained environment than ZFS.
- e12e 13y agoHm, how about nilfs2? http://www.nilfs.org http://www.nilfs.org
- Tobu 13y agoBtrfs snapshots are implemented using COW-shared trees (multiple trees for data and metadata). They can't be implemented with hardlinks, that would be a very leaky abstraction.
- beagle3 13y agoWhy is block level deduplication worse?
- wtallis 13y agoI'm not aware of any volume snapshot system that presents the history as a plain directory tree. At best, you can use some special mount options to mount a snapshot, but you generally have to use a special tool particular to that filesystem in order to access a snapshot, and creating the snapshot always requires such a tool. There's no standard Unix way to create or access volume snapshots. Time Machine histories can be created, accessed, and analyzed entirely with standard tools except for the modified `ln`.