Re: possible new feature: unrm ?

[neitzel%hackett.marshlabs.gaertner.de@localhost (Martin Neitzel)]

> There are scripts which will create and remove a set of snapshots on 
> zfs, which would be pretty much what you have in mind.
> [...]
> Traditional Unix filesystems don't support this well, I am afraid.

Well, "traditional" is a vague term, but we in {Net,Free}BSD land
have the McKusick's FFS softupdates+snapshots since NetBSD-2.0 and
FreeBSD-4 in our default filesystem.  That is: two decades now.
(Sorry, OpenBSDlers, you didn't bother.)

If you've never used it before, do yourself a favour and give it
a spin.  fssconfig(8) has an easy-peasy example how to create a
snapshot, use it, and get rid off it again, doable in less than
five minutes.

If you are inclined to read more on it, there are several papers
available, for example:

https://www.usenix.org/legacy/publications/library/proceedings/bsdcon02/mckusick/mckusick_html/index.html

And while I'm at it:

(1) In *BSD land, we also get nighlty RCS revisioning of all our
adminstrative files (/etc and more) out of the box.  (Watch your
daily mail and /var/backups if you haven't noticed before.)

(2) DragonFlyBSD's "HAMMER" filesystem lets you review and unroll
any atrocities against files or directories with "sync update"
resolution (30 or 60 seconds) along the entire day.  Around 3am,
the past day's details get condensed into a summary snapshot --
these will be kept for 180 days.  So you get half a year of revisable
and undo(1)able history of your files, out of the box.

						Martin Neitzel