[whitegrape]

Have an immutable filesystem, where "deletes" are recoverable by going back in time. At least until you do a scheduled "actual delete" that will reclaim disk space.

Another option (though last time I tried it, it didn't work..) is something like libtrash: http://pages.stern.nyu.edu/~marriaga/software/libtrash/ Deletes become moves and you can really delete when you like.

Practically speaking, if you're quick an 'rm' isn't totally destructive even without backups. There's a good chance your data is still there on the disk, it's just not associated with anything so it could be overridden at any point. Best to mount the disk read only and crawl through the raw bits to find your lost data (I recovered a week's worth of code this way several years ago).

[derekp7]

My favorite answer to the common interview question: "What was your biggest mistake, and how did you recover from it?" Answer: Back in 1993, I once deleted a critical data file. Fortunately, the AIX host was sitting next to me, so I quickly reached over and flipped the power switch off. The strategy being: writes were buffered and flushed out periodically, so hitting the power switch prevented that last write from hitting the disk. And if this didn't work (and caused more file system corruption), well I would have needed to restore from backup anyway.

[nickpsecurity]

That's great. Straight out of an NCIS episode except it actually makes sense this time. :)

[toomuchtodo]

> At least until you do a scheduled "actual delete" that will reclaim disk space.

And then you "actual delete" is where the data loss occurs :D

[Avshalom]

Right but if you delete your entire file system there won't be anything to come along and do the "actual delete" so you're safe until some one comes along with a rescue disk or otherwise mounts it to a system that knows how to deal with this.

At the very least when you rm important-file.txt instead of importanr-file.txt you have a chance.

[wruza]

Pre-delete would already hide files from apps and services for them to "fail fast", and actual delete would be just "i'm running fine for two days". Of course this implies that active open files should not be pre-deleted on unix at all (at least not by rm process). Even if you delete the entire filesystem with backups, there will be a chance to boot into recovery mode and undelete everything back. We can even go further and apply small-file-versioning on fs level to prevent misconfig accidents in /etc.

That's very simple and powerful, I can't tell why it is still not implemented today.