A few times in the past I've been caught recommending Microsoft products, only to have it come back and bite me when things don't work properly. Recently I had this experience once again, when I recommended the use of offline files in Windows 7. For some reason, offline files has never been extremely stable in Windows. Simply doing a Google search about offline files and problems in Windows XP will bring up more than enough reading material. Supposedly, offline files has been reworked in Windows 7 and the stability issues ironed out. But this doesn't seem to be the case in reality. I discovered the hard way, that offline files in Windows 7 is as quirky as ever. In my situation, I helped set up offline files to synchronize a network drive in Windows 7. The main purpose of synchronizing was the storage of a PST (personal storage) file for use in Outlook when the network drive was not connected. In Windows XP, synchronizing a PST file was not supported. In Windows 7, it is supported, but in my case it only worked for 2 days (just fine), then it broke on the third day without warning. Eventually, Windows reported that the PST file's offline status was "unavailable" in Sync Center, and the file could not be opened by Outlook when running in offline mode (when Windows uses the offline cached copy of the file). When the network drive is back online, it works fine.
While troubleshooting this issue, we soon discovered the other various quirks with offline files in Windows 7. One idea was the delete all of the local cached offline files, and let it resynchronize again from scratch. We soon found that deleting the cached offline files is quite a challenge. Repeatedly clicking on the "Delete offline files" button in Sync Center would finish successfully, however it still reported 2 GB of disk space being used. Each time the "Delete offline files" button was pressed, the amount of used disk space would decrease, until eventually only 300 KB was left. Doing some research on Google turned up this as a known quirk as well. One solution is to "rebuild" the offline files cache database with a registry setting, to get the usage back to 0 KB. The registry entry is supposed to force the database to rebuild.
In summary, I'm not impressed at all with offline files. Especially when I compare it to solutions like rsync in Linux, which works perfectly every time, and works very very well. Why can't Microsoft learn from previous mistakes, and fix their software? It's embarrasing to recommend these products and sell the idea of using Microsoft software to somebody, when it will work for a while then break all of a sudden out of the blue. I should have learned, that it's OK to recommend Microsoft software if absolutely necessary, but I no longer guarantee that it will work as designed.