Subject: Re: revisiting quotas
To: Manuel Bouyer <>
From: Robert Elz <kre@munnari.OZ.AU>
List: tech-kern
Date: 06/12/2000 21:29:26
    Date:        Sun, 11 Jun 2000 19:01:03 +0200
    From:        Manuel Bouyer <>
    Message-ID:  <>

  | Ha ok. It was not in the superblock, but in the quota file itself.

That must make it even harder, as the quota file can't tell if the
filesystem has been altered - quota files can even be dumped, and
restored years later...

  | No, because quotacheck runs on the raw device which isn't available for mfs.

quotacheck only uses the raw device for speed (avoiding the extra
layer of buffering).  It will read exactly the same data through the
block device (on any filesys).

(Aside: mfs ought to be able to have a raw device as well, and probably

  | Sure, but the update of the quota file doesn't take much time here.

No, if you don't have many users owning files (and even more so if
no updating is actually needed).   If you have 30K users, and their
usages are all out of date (incorrect) the quota file update will
take longer than the scan on almost any sized filesystem I can imagine.
(Partly because to allow for the possibility that quotacheck is being
run when quotas are enabled already, a quotactl sys call is done for
every correction).