ANTenna Blog -- Apple

Word's going around of an apparent data-destroying bug in the way Apple's new Snow Leopard OS handles guest accounts. SMBs that need to provide network access to temp workers, visitors from another office, or other non-permanent denizens of the office should be aware of the danger and take appropriate precautions.

Multiple topics on the Apple Support Discussion boards contain reports from people who logged into the Guest account on their Snow Leopard machines -- accidentally or on purpose -- and then found that when they logged back into their regular account, all their data was missing. It's not that the regular account was gone; rather, it was as though it were a newly created account with no files in it yet. The discussion threads first started showing up within a few days after Snow Leopard shipped, but they're all still marked "not answered."

The problem could be related to the fact that data saved in a Guest account is deleted by default when the guest logs out. For some reason, Snow Leopard may be handling the regular account as though it were a Guest. Some have suggested that it's a glitch in the account upgrade process -- that there's an incompatibility between the way Leopard handled Guest accounts and the way Snow Leopard does, and if the Guest account was enabled in Leopard when the system was upgraded, the incompatibility can trigger the problem.

There's also as yet no real post-disaster fix for the problem, unless you're lucky enough to have a recent backup you can restore your data from. An article on MacFixIt offers some good advice on how to prevent the problem in the first place, though:

• Easiest is to just disable the Guest account. Launch System Preferences, choose the Accounts icon, click the lock and enter an administrator password to make changes, select the Guest account, and make sure the Allow Guests to Log In box is unchecked.

• Those who want access to a Guest account should at the very least disable the existing one, as above, and then re-enable it. That may remove whatever incompatibility is causing the problem. There's really no safe way to test if it worked, though.




• For SMBs that do need temporary accounts, the best approach, at least until Apple releases a patch, is to just work around the Guest account. Administrators can either set up a personal account or a permanent Visitor account, make it Standard, and use parental controls to limit what the user can do. It's extra work, and it means the guest worker's data must be manually deleted when they leave. But it's a darn sight better than losing an account's worth of data.