> every time I start SUP these days all files get updated (what takes quite
> a long time). Is this a problem of "sup.netbsd.org" or with my SUP mirror
> "ftp.uni-paderborn.de"? 

I think it was problem of "sup.netbsd.org".

problem of "sup.netbsd.org' makes "sup on ftp.uni-paderborn.de" fail.
(i.e. sup's "when" file is not updated on ftp.uni-paderborn.de.)
So, next sup on ftp.uni-paderborn.de updates all files.

It causes "sup on your host" to update all files, because all files
on ftp.uni-paderborn.de are updated by utimes(2), and sup checks
not only st_mtime, but also st_ctime.

> Because of the recent permission problems
> on "sup.netsd.org" I asked the admin of "ftp.uni-paderborn.de" to use
> "sup -o ..." a few days ago. Could that be the reason?

No.
sup on ftp.uni-paderborn.de would update all files whether with "-o" or not,
because st_ctime of all files on sup.netbsd.org were changed recently.

P.S.
problem on "sup.netbsd.org" was fixed.
--
soda@sra.co.jp		Software Research Associates, Inc., Japan
(Noriyuki Soda)		   software tools and technology group