[891] in testers
Re: /srvd
daemon@ATHENA.MIT.EDU (daemon@ATHENA.MIT.EDU)
Sat May 26 14:53:56 1990
Date: Sat, 26 May 90 14:53:30 -0400
To: dkk@MIT.EDU
Cc: Ezra Peisach <epeisach@MIT.EDU>, testers@MIT.EDU
In-Reply-To: David K Krikorian's message of Sat, 26 May 90 02:47:13 -0400,
From: Richard Basch <probe@MIT.EDU>
This doesn't directly comment on the /?rvd/.rvdinfo, but it addresses
your message about the urvd information in a different way; I fear that
you have not fully thought about the required Hesiod information, and
the contents of this message will somewhat demonstrate that the usrlib
information will have to be different from what you are thinking it
should be.
For the propogation to work, the following Hesiod information should
exist (I am only stating the version numbers of the packs):
syslib 7.0
usrlib 6.4
There are no packs that you can substitute in place of the urvd packs
when you do the rvdexch, so this is probably the best way of going about
it. Also, if an activate is done on a server, the urvd binaries will
still be compatible. In 6.4, everything is symlinked through /srvd,
except on machines on which "mkserv" was run (thus, only Athena
Operations' servers). This way, the Athena servers will not risk the
possibility of packs causing lock-ups on the servers if binaries are run
from the new packs (as it is more likely you will be using binaries from
6.4 packs).
There are various technical reasons why the above mixture will probably
be better than the symlink existing. However, after you feel confident
that everything has been updated, I would recommend changing the usrlib
information to be something... I chose /urvd -> /srvd/usr in order to
give time for people to convert their dotfiles not to rely on /urvd. We
still wanted to have usrlib information and not modify activate to only
use syslib information -- this way hacks could be done to supply a small
"patch" pack, if one was required. /srvd has a "patch" directory over
which other filesystems could be mounted. On the AFS packs, however, it
will require hand-frobbing to make /srvd/patch point to somewhere else,
since overmounting is not allowed on /afs; but this is rather easy to do.
I also object to adding more /urvd compatibility than the simple stuff
that is required; this is a transition to a one-pack environment; adding
the .rvdinfo faces more risk; the "track" subscription list must be
modified, as does the stat-file. In addition, it is rather late to
consider changes that are not of the utmost importance; each last minute
item that is placed on the packs now requires a fair amount of work;
several sets of packs must be modified (master read-write AFS packs,
read-only replicas, RVD copies of the AFS packs), and then you will have
to keep your RVD's up-to-date -- we promised that we will adjust the
.rvdinfo information, as needed, and an additional .rvdinfo means that
it too will have to be modified (or it be a symlink up to the master one).
-Richard
