[NILFS] Current Status

Current Status

Basic POSIX file system features
Snapshots
- Automatically and continuously taken, you can retrieve past state of NILFS file system.
- No limit on the number of snapshots until the volume gets full
- Mountable as read-only file systems
- Mountable concurrently with the writable mount (convenient to make consistent backups during use)
- Quick listing
- Easy administration
Background Garbage Collection
- Can maintain multiple snapshots
- Selectable GC Policy, which is given by a userland daemon.
Quick crash recovery on-mount
Read-ahead for meta data files as well as data files
Block sizes smaller than page size (e.g. 1KB or 2KB)
Redundant super block
Online resizing (since Linux-3.x and nilfs-utils 2.1)
Related utilities (by contribution of Jiro SEKIBA)
- grub2
- util-linux (blkid, libblkid, uuid mount)
- udisks, palimpsest
- Filesystem label (nilfs-tune)

Smarter and more efficient Garbage Collector
fsck
Extended attribute
POSIX ACLs
nilfs-debug: offline debug tool to analyze broken volume
Better support of synch operations (fsync, etc).
Performance improvement (Better Block I/O submission)
Checkpoint rollback
Checkpoint based remote replication
FITRIM
Less frequently updated superblock for flash devices.
Optimization for silicon disks (e.g. SSD)
Offline resizing
Online defrag
Faster inode allocation
atime
Shred file along with its past versions
Design document and better developer support
Better support of mmap and direct I/O.
System/package undo tool support: snapper, etc.
Unified user command ``nilfs'' (rather than separate commands like lscp, rmcp, mkcp, etc).
"Time-based" tools (e.g. tls, tdiff, tgrep, tfind, ttar and so on. They come from the Elephant file system)
Time-machine like browser
Time slider

Long term TODO list: