On Fri, 10 May 1996 14:51:37 EDT Stan Horwitz <[log in to unmask]> said: >I was just told by one of the people who runs the system on which we run >Listserv that if we were to shut Listserv down to back it up, it would >be down for several hours Uh? What is your backup device, a 3410-1 with a tape mount in between and the operator watching a movie that's so good he can't get away from the TV until it's over? :-) LISTSERV 191 is typically 20-30 cyl at large sites, it should only take a couple minutes to back up. Alternatively you could create a shadow 191 minidisk and have LISTSERV copy the files over once a day, then release and detach the disk. You could then back up this alternate minidisk instead of the 191. In general the problem of making reliable backups on a live system is unsolved. The system that comes closest is OSF/1, the backup program can tell the system to take a snapshot of an entire partition so that the backup program sees the files as of this instant regardless of any further change (a bit like SFS, but for the entire file system). But not even that ensures that the snapshot is in a stable state. An application could be in the process of appending to a file, etc. Any application that can recover automatically from a power outage should recover from restoration of such a backup, but ordinary end users seldom write applications this way :-) As far as I know, OSF/1 is the only system that can do that. I hope and assume that TNFS will also have this ability under VMS. Eric