Re:Should We Abolish User Access to rm? (2011)
by keenerd on Tuesday July 30, 2013 @04:23PM
(#6129773)
> I suppose every journaling FS already includes everything necessary for it.
Depends. Ext seems to use a F̶I̶F̶O̶ LIFO for the empty block list. It can make recovering data more tricky.
Last time I tried to recover some deleted data, it was about an hour after the delete took place. The recently deleted blocks were the first over-written by normal background tasks and everything I wanted to save was gone.
Every file more than a few hours old was easily recovered, right back to projects I had deleted a year previously.
edit: Thanks.
Re:Should We Abolish User Access to rm? (2011)
by colanderman on Tuesday July 30, 2013 @04:25PM
(#6129790)
I think you mean LIFO? A FIFO would imply that your old projects (first in) would be re-used soonest (first out).
A file system might implement `rm` so that it does not lose data outright, but keeps a few recently deleted files intact for undeletion. I suppose every journaling FS already includes everything necessary for it. E.g. http://extundelete.sourceforge.net/ uses ext3/ext4 journals. AFAICT NTFS undelete works the same way.
Some file systems have explicit snapshots and other tools that facilitate rolling back changes: xfs, ext3, ext4 all support snapshotting on Linux when run under LVM. It's even better than undelete.