Using Sync Services with Remote Homes

After receiving several reports from users reporting issues with remote homes and sync services and forwarding those details to Apple Development Support I got the following response back. Unfortunately this is one aspect I have very little control over and will not be able to change the current behaviour.

Sync Services does work on a network home, with a number of caveats and limitations:

- All client machines should be using the same OS version.

- Only one machine can sync at any one time (this is by design).

- There is no fairness algorithm, so one machine can steal the lock.

- We generally expect users to log in to only one machine at any one time.

- If using a network home, your data is synchronized between machines by virtue of the network home, 
so Sync Services is unnecessary for certain topologies. It is needed for the case where the user
 is syncing to a machine with a different home directory.


As far as we are aware, none of these limitations will result in crashes. We will throw exceptions in some cases, 
when the sync cannot start, and sync clients that don't catch those exceptions correctly will crash, but that is a 
3rd party app bug. We'd be interested to see crash reports implicating Sync Services.

This behaviour is not changed by Snow Leopard.

We understand that it would be great if this "just worked" but it's actually a fairly complex problem to solve, 
because applications have a differing approaches to mixing OS versions and network homes, 
hence the restrictions/limitations.

Problems with remote homes usually manifest themselves on the client with accessing iSync or Address Book Client's System Preferences. The following error can be observed in the Console log on the client

SyncServer[940] Can't obtain lockfile to run sync server, a sync server is running on the computer otherComputer.local and shares this home directory 

I haven't found a definitive solution for this issue so far. However I believe logging out from all computers you have logged in and trying to log back in to the client you intend to use may resolve this issue.

It has been suggested to delete the Lock folder in ~/Library/Application? Support. I haven't tried this myself and can't comment on any possible side effects. You do this at your own risk.