Has anybody had success trying to split a single HP 3000 system into two different OS versions by using two sets of disks? There is no need for sharing of information between the two operating systems, and they would run independently of each other at different times of the day.

Guy Paul replies:
This is certainly possible, as we have done this in the past for customers who couldn’t tolerate any downtime for OS upgrades. Hence, we came up with a solution to have a duplicate set of SYSVS discs that we upgraded while they were still on the old OS. Come day of the ‘real’ OS upgrade, we brought them down, stored off any modified files, switched over to the new OS, restored any modified files and they had an OS upgrade in about 45 minutes. So it is possible.

You should probably consider using BULDACCT to synchronize the accounting structure.

Gilles Schipper adds:
This should be entirely possible. I do this sort of thing all the time. By simply booting from the appropriate boot path, you can do exactly as you wish. In fact, I have even shared common volume sets among different LDEV 1 system volume sets, with different MPE versions.

What's the name and syntax of the Posix utility that allows you to assign a new file, give the file the same name as the one you're replacing—and the new file will replace the old file when the last user closes it?

Andreas Schmidt replies:
You want to use mv, a utility to rename and move files and directories. The syntax is

mv [-fi] file1 file2
mv [-fi] file... directory
mv -R|-r [-fi] directory1 directory2