Often people ask about some tips about synching your devices with your computer. Mine is simple: Don't!
Of course, I'm not talking about music, videos or pictures. This is mostly targeted at mails, contacts and calendar events. Over the years, I've had many devices that could be synchronized with my computer for all kinds of data. In the end, the sync operation will eventually lose data or duplicate it. It's a matter of time...
In theory, the process is simple: Check what is different from the two devices, and make it the same on both. The basic rule is: Which one is the newest and update the oldest one. The thing is that is doesn't always work the way we expect it to...
Case 1: Twos items are found to be the same based on some GUID number. The newest item will replace the older item on the other device.
Case 2: The two items have been updated since the last sync, so we now have a conflict. Depending on the sync configuration or the user's choice, one will be overwritten by the other
Case 3: The item has been deleted on one device, and the other item will be deleted as well on the next sync...
Case 4: The original item has been recreated by the user, but now has a new GUID number, which the sync operation will not recognize even if the content is the same. Sync operation will then duplicate the item, or even delete both items depending on the sync configuration.
All kinds of things can happen over time: Contacts are copied into another account, calendar events are moved into another calendar, emails are downloaded after reconfiguring the device...
Basically, if you have important information that you don't want to lose, don't sync.
So how do we share contacts, emails and calendar events between devices and computers? Just connect to the server as a client. Most email services now offer IMAP which will do just that. As a bonus, your email services will also handle contacts and calendar events (GMail, Exchange, etc...). What you have on your device is just a picture of what is on the server. This way, there is not confusion possible as if you delete it from your iDevice/Computer, it will be deleted on your server. All other devices will reflect that change by making a new snapshot of the server the next time they will update the content.
Another argument against synching is that your device may do some operation that you did not expected when synching. For example, on a Blackberry Bold, the calendar synchronization will delete events older than 60 days by default. At the first glimpse, it looks like the phone will only synchronize events that are newer than 60 days. But in fact, by deleting old events in the phone's calendar, the sync operation will extend the deletion to the server (Exchange servers from my personal experience).
Synching can be a nightmare when things go wrong. So you have to make backups everywhere to avoid losing data.
Use an Exchange/IMAP server when possible. If you service does not provide IMAP and only POP3, switch to another service that will provide that feature. It can be a hassle to make the switch, but losing all your 1500 contacts or that really important email will feel much worse when it happens.
Venting from another sync issue today