The other day someone asked me about the backup of MacOS X 10.5 and open file support.  Thought instead of just responding via e-mail I’d also note this publicly in case there were any other questions.

There are different forms of open file management.  One is the type you find with some of the Microsoft Windows operating systems — using a feature known as VSS (Volume Shadow Copy Service.) For other operating systems, in particular the Linux and UNIX types of operating systems (and MacOS X is of this type), you can certainly read a file while it’s open which is the core definition of “open file management.”  It’s what Apple advertises in this context.  But there’s no concept of what VSS offers.

What we offer is the ability for the user to specify how they want to handle locking associated with open files.  There are options that a user can specify in the RRC with respect to what you do in handling locked files – up to and including waiting forever until the lock is relinquished.