Re: [9fans] Plan 9 wiping itself?

["Russ Cox" <rsc@swtch.com>]

On Nov 24, 2007 1:43 PM, Uriel <uriel99@gmail.com> wrote:
> Somebody was asking why replica sucks?

It's a bug in a shell script, which caused sources to look like
some files went away and then got recreated.   This happens
occasionally if the replica update programs that run at Bell Labs
get interrupted or the sources disk fills.  It doesn't cause data loss,
scary though it may look.

In this case, replica actually recreates all the files it deletes,
and it refuses to delete any file that had been locally modified,
so no information would have been lost.  (I tested this earlier
today on my own system.)

I assume that your vague references to replica destroying people's
systems is in fact referring to earlier times that this kind of sequence
has happened.  Again, replica won't touch any file that it didn't create
and it also won't delete any file that has been changed since replica
put it there.  I really don't expect very much of you, Uriel, but I didn't
expect FUDmongering.

For what it's worth, I made some changes to pull today to
eliminate spurious warnings about "locally modified" files in the
case where the local file and the sources copy are identical.
This avoids conflicts in the common case where one does

   9fs sources
   cp /n/sources/plan9/some/file /some/file

and then later run "pull" to update your system.  It also avoids
conflicts in the common case where you make a local change,
submit a patch, the patch gets installed, and then pull wants to
propagate your change back down from sources to your local machine.

I also changed pull to ignore deletions if the supposedly-deleted
file has been recreated.  This will make pull skip over a sequence of
"delete then recreate" entries in the log.

Russ