https://github.com/vi/fusecow
Simple single-file FUSE implementation of copy-on-write
https://github.com/vi/fusecow
Last synced: 4 months ago
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Simple single-file FUSE implementation of copy-on-write
- Host: GitHub
- URL: https://github.com/vi/fusecow
- Owner: vi
- Created: 2011-01-23T01:48:08.000Z (over 15 years ago)
- Default Branch: master
- Last Pushed: 2014-08-14T21:52:04.000Z (almost 12 years ago)
- Last Synced: 2025-04-15T14:13:32.942Z (about 1 year ago)
- Language: C
- Homepage:
- Size: 180 KB
- Stars: 10
- Watchers: 5
- Forks: 5
- Open Issues: 2
-
Metadata Files:
- Readme: README
Awesome Lists containing this project
README
Simple single-file FUSE implementation of copy-on-write using sparse files as storage to copyup
Example session:
# mount | grep "on / "
/dev/sda8 on / type reiserfs (rw,user_xattr,usrquota,acl)
# touch mountpoint_file
# ./fusecow /dev/sda8 mountpoint_file write_file
# reiserfsck mountpoint_file
Replaying journal: Trans replayed: mountid 636, transid 14679519, desc 901, len 2, commit 904, next trans offset 887
Trans replayed: mountid 636, transid 14679520, desc 905, len 1, commit 907, next trans offset 890
...
# ls -lh
-rw------- 1 root disk 30G Jan 22 17:01 mountpoint_file
-rwxr-xr-x 1 root root 29G Jan 23 06:01 write_file
-rwxr-xr-x 1 root root 472K Jan 23 06:01 write_file.map
# du -sh *
32M mountpoint_file
31M write_file
281K write_file.map
# mkdir mnt && mount -o loop mountpoint_file mnt
# dd if=/dev/urandom of=mnt/usr/local/etc/qqqqq bs=1M count=32
# umount mnt
# fusermount -u mountpoint_file
# du -sh *
0 mountpoint_file
65M write_file
289K write_file.map
# ls /usr/local/etc/qqqqq
ls: cannot access /usr/local/etc/qqqqq: No such file or directory
# ./fusecow /dev/sda8 mountpoint_file write_file
# mount -o loop mountpoint_file mnt
# ls -lh mnt/usr/local/etc/qqqqq
-rw-r--r-- 1 root root 32M Jan 23 06:05 mnt/usr/local/etc/qqqqq
Limitations:
1. Slow
2. Cannot grow files yet
3. Unstable