On Sat, Feb 24, 2018 at 07:20:48PM +0100, Gionatan Danti wrote: > Hi all, > I have a question on how CoW/reflink works when used on busy files, > as vm image files, databases, ecc. Define "busy file", please. > In short: can reflink-copy be used to create a crash-consistent > snapshot of, say, a busy vm disk file? If the file is being actively written, then the clone will not be consistent. > Or the db/vm/whatever should > be quiesced before taking the copy (ie: similarly to how lvm call > fsfreeze during the snapshot)? Yes, it's just like any other snapshot process - you have to quiesce everything that is writing to the file before cloning it. i.e. the data in the file needs to be in a stable, consistent, unchanging state if you want the clone to contain consistent data... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
