I don't see how rsync will work here, during the sync time, the new file won't be available (entirely) from the other machines. As I understand it, the OP is lo

I don't see how rsync will work here, during the sync time, the new file won't be available (entirely) from the other machines. As I understand it, the OP is looking for something that will sync while already serving up the file, presumably giving priority to syncing the parts that are already being requested by clients. (which will be the beginning of the file most of the time unless clients will be using partial downloading) I've never set one up myself, but a clustering file system might work, e.g. OCFS: http://oss.oracle.com/projects/ocfs2/ http://oss.oracle.com/projects/ocfs2/