[34] in Release_7.7_team
Re: Expunging old files
daemon@ATHENA.MIT.EDU (yandros@MIT.EDU)
Tue Mar 15 15:07:09 1994
From: yandros@MIT.EDU
Date: Tue, 15 Mar 94 15:06:46 -0500
To: release-77@MIT.EDU
In-Reply-To: "[32] in Release_7.7_team"
Perhaps you don't particularly want my input at this point, but I
suspect that noone here minds getting rid of extra transactions *too*
much. :-)
You need to do user expunging or mount a *LARGE* education campaign.
*Lots* of people don't know what expunge is or what it does; I've
answered enough of their questions in SIPB and OLC. Also, even once
they know what it is, they usually decide to wait for the system
expunger to delete the files unless they need the space immediately
(unsurprisingly).
Running expunge on the `average' user's homedir will be a noticable
slowdown; I'd be pleasantly surprised if someone somehow got the
average down to ~30 seconds. (although I like Gary's idea of a
dotfile cache)
Running expunge for files deleted three days ago on logout is not
equivalent to the `current' system; there are conditions where files
that would be deleted under the current system would not be deleted
under this new system (anytime the user doesn't log in for three days,
in fact.) You may not care about this distinction.
Running expunge for all deleted files on logout is not equivalent to
the `current' system; files will be deleted which might not otherwise
be deleted. This does not solve the `willies' you get from thinking
about people losing files when they log back in to undelete, since the
file is already gone, but it takes the delay away from the login time
and moves it to the logout time (security problem with unattended
workstations?) OldFiles is *NOT* a solution to this, since if the
person cares, it's usually becuase they've been working with the file,
and OldFiles will be too out-of-date to be useful. You may not care
about this distinction.
OldFiles is *not* a replacement for the delete functionality; more
files that are accidentaly deleted are being worked on, and OldFiles
is out of date. I make this claim based on personal experience with
users in SIPB and OLC (not personal experience; I don't use delete.).
I could easily be wrong, but I'm not. :-)
That said, I'm a bit confused as to why expunging can't be simply
distributed to as many machines as you like, each dedicated to a
particular chunk of afsland. Would that be too slow? There'd be some
syncing issues that would need tuning, but that doesn't seem
complicated to fix.
Personally I like expunging things older than a day on logout best;
OldFiles will catch the slack from three to one days, and a
dotfile-cached expunge on logout shouldn't take too long. The
accompanying user education program should teach users to run purge
every so often anyway; that should suffice for catching things that
might be missed by the cache mechanism.
thank you
chad
