Re: Bug#201023: dosemu: purging doesmu wipes out all user data under /var/lib/dosemu)
On Mon, Jul 14, 2003 at 07:03:22PM -0600, Jamin W. Collins wrote:
> On Tue, Jul 15, 2003 at 02:06:59AM +0200, Emile van Bergen wrote:
> > On Mon, Jul 14, 2003 at 05:45:23PM -0600, Jamin W. Collins wrote:
> > > What about data file created by the package through its normal
> > > operation. Such as log directories, or user account files? Again,
> > > these are created by the application directly, not the user. Which
> > > category do these fall in. Since they don't fit the categories
> > > above, should they be left behind on a purge?
> > Well, for logfiles and similar things I'd say the question of what to
> > do when --purging is a bit less controversial than for category 3.
> > For files created during normal operation of the package I'd ask
> > myself: is this created by the package on behalf of the user?
> This is a very fine line. If the user entered data that is stored in
> the files, is it on behalf of the user and thus user data? Case in
> point is the Jabber package. Each user's roster and account are stored
> in spool files. Should these be deleted on a purge?
It's a hard question. I don't have an answer to that. I can only say
that any data that exists as a result to user creativity and/or action
should be treated with due care and prudence. This may or may not be
true for Jabber spool files.
Again, I think erring on the safe side (in favour of /not/ removing
files containing a result of user input) is more useful, considering the
relative frequencies of the case that you reinstall a package, and that
you abandon use of a package forever and that whatever you entered
looses all use. In the latter case, it's easy to take care of the
remains, being guided by dpkg warnings about non-empty directories.
> > For log files, this does not hold. In most cases those are not the
> > primary output of the tool when operated by the user, but instruments
> > to gather statistics and monitor the tool's operation. I'd expect
> > --purge to delete such files.
> But they are neither conffiles or explicitly part of the package
True, I agree I missed that category. But that doesn't invalidate my
point, which is that data 'belonging' to the user, even if hard to
define, should be held sacrosanct.
> > It's only user data that should be excluded from --purge, for the
> > simple reason that there should be nothing holier to a computer
> > program than user data.
> And "user data" can be defined in a multitude of different ways. I'm
> sure to someone out there the spool files the Jabber package creates are
> "user data". The term sadly is overly general.
If creating spool files is the purpose of the package (it probably
isn't) or a side effect of its use that's useful in other contexts as
well (I don't know), then yes, it's enough 'user data' to avoid deletion
Aside, I think that the notion of ownership by the package of a file is
stronger than it can ever be in case of a directory. A directory is a
generic container and thus never only useful to the package that stores
files there. A file can be only useful to a certain program if it eg.
contains too many implementation details to ever be useful to a human or
another program. But that's an entirely different issue.
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