Working with multiple homes

A recent discussion about “mobile home directories” on the mailing list prompted me to respond with the following article. It addresses the issue of working with multiple homes, how to approach syncronoization, current technologies, and what would like to see developed.

Unfortunately, complete synchronization will not be included with 10.4. I just called Apple to confirm and have been informed that although this new feature will synchronize your home folder, everything will not be synchronized. Most significantly, this will not include the Library folder; which is disappointing because that is actually the only one that I care about.

This issue is a big one for many users. Many people have a Powermac at work, a Powermac at home, and carry a Powerbook in between. Most people like to have the same work environment on all their systems. They also like to have access to the same data on each system. Setting up application preferences, OS preferences, and application data (calendars, contacts, playlists, etc) across multiple machines and then keeping them in sync is a difficult task. Doing it manually is asinine, but fairly consistent and successful result can be achieved by using a file synchronization utility. The big frustration however is that these generic utilities do not know how to merge the files and can only replace with the most recently updated file, thus requiring that you only edit/update/work on one machine at a time.

A working example of this is a daily routine I have used off and on. I get to the office in the morning and connect my Powerbook to the network. I then run my synchronization scripts. This copies my preferences and other data files over to my Powermac. Next, I mount one of the volumes on the laptop onto the Powermac. I am now ready to work for the day. My calendar has all of the latest data, my address book has the latest data, my must playlist has all of the latest data, and I have access to all of my files. Then, at the end of the day, I run the entire process in reverse. And, if I had a Powermac at home, I would then have to do this entire process an additional time.

The key however is the discipline of only editing and updating one computer at a time until a synchronization is done (read “inititated,” not “completed”). For this reason, I have usually limited myself to “read only” access on my Powermac and done all of the editing and imputing on my Powerbook.

There are a few technologies that solve some of these issues, but a perfect solution does not yet exist, especially for the average user.

For contacts, the best solution would be to implement an LDAP server on my remote server and then do all imputing via a web interface. Each address bookclient on each computer would be read only, accessing the data from the server and always having the latest data. A big catch however is that you do not have the data you need when you are offline. This could be solved however if Address Book were designed to keep a cache of the data; something that would be quite easy to do.

For your calendar, iCals publish feature appears to be a solution by immediately updating the data on a remote server for all clients to read from, but this has no advantage over my file-copy method as it can only be done one way. Subscribing to calendars is a read access only arrangement.

For files (both preferences and all other), it is easy enough to have a repository on a remote server that all of your machines synchronize with, but it still isn’t flawless, as real-time synchronization isn’t possible/reasonable and non-real time results in inconsistencies.

Thus, an ideal solution would be one that was built into the operating system. It would:

1. allow you to choose what level of synchronization you wanted (what is included)
2. choose what the remote device would be (preferably a remote server but you should also be able to establish a simply synchronization relationship with two independent workstations)
3. would cache everything
4. most importantly, would auto update

This last item (auto-update) is the key. It should be configurable to check for updates at various intervals (such as daily or hourly) and then retain a time stamp to check against for automatic updating when an attempt is made to access the data and the data is older than a determined time.

.Mac takes care of most of these, but is still laking in many areas

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