What's the process to svnsync a larger repository

I'm learning some gotchas with svnsync this week. As per my typical method
of learning I try 3 wrong ways before finally realizing the right way to do
most things.

We have about a 1GB svn repo on Ubuntu at -r 3738, and I'm trying to get it
mirrored on Win 7 running VisualSVN.

I created the mirror repository fine, ran svnsync init and svnsync sync on
it, then as it started going from -r 1, -r 2, -r 3..., I realized it would
take a week or more to fetch all nearly 4K commits.

So I stopped it, deleted it, started over and did an svnadmin dump -->
svnadmin load from the dump -- which ran/imported much faster, but now when
I try to initialize the sync, I get

svnsync: Cannot initialize a repository with content in it

D'OH! I forgot to svnsync init after creating the empty mirror repo. Whoops.

So, my question is, before I whack a perfectly fine "almost mirrored"
repository, can I svn propset -r 0 all the stuff needed by svnsync
manually, to start syncing at -r 3738?

Or can I set up the repo again (svnadmin create immediately followed by
svnsync init) and then svnadmin load (since load from a dump is so much
faster)?

It would seem odd that the only way to mirror a repo is to replay
everything from -r 0.

Thanks for your guidance!

Geoff

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