Re: [Savannah-hackers-public] Setting up bzr+ssh on Savannah.

[Sylvain Beucler]

On Wed, May 05, 2010 at 01:17:45PM -0400, Paul Smith wrote:
> On Wed, 2010-05-05 at 01:56 -0700, Karl Fogel wrote:
> > Karl Fogel <address@hidden> writes:
> > >>I'm personaly not so sure about asking people to re-push and such, but
> > >>up to you.
> > >
> > >Well, I'll have to work out the exact recipe, but if people's
> > >already-pushed changes are going to disappear, they need to be warned
> > >and informed of how to fix it.  I may be able to avoid that by doing the
> > >pushes for them, we'll see.
> > 
> > Turns out we shouldn't have to deal with any re-pushes -- the entire bzr
> > repositories all together are around 1.3GB.  We can just go read-only
> > long enough to copy that amount over.
> 
> For 1.3G it's probably not worth it, but for migrating large data sets I
> have found rsync to be invaluable.
> 
> What I do is rsync to the new system while everything is still online
> and running: for this rsync you don't care whether the result is
> coherent or not.  You can continue to do this every so often right up
> until the time you want to move (plus this gives you a good feel for how
> long the eventual downtime will be).  Then when you're ready you shut
> down write access to the data and do a final rsync, which will be very
> quick typically since it's only copying the changes since the last
> rsync.
> 
> Then bring up the service on the new system.
> 
> This lets you lock the service from write, and avoid problems with
> changes going missing, while still having a quick transition rather than
> waiting for all data to copy across.
> 
> 
> WFM!  Thanks for all your work on Savannah, folks...

This is my technique of choice as well, I recommend it :)

Also: Karl, you'll want to test the creation of new bzr repositories
from the Savane interface in the new environment.

-- 
Sylvain