You're missing a crucial detail for an absolutely safe RENAME
- CP LINK sharedDisk xxxx 111 M
- ACCESS 111 N
- COPYFILE ABC EXEC A ABC NEWEXEC N (OLDDATE
- RENAME ABC EXEC N = OLDEXEC N (NOUPDIRT
- RENAME ABC NEWEXEC N = EXEC =
- RELEASE N (DETACH
The trick is NOUPD in step 4.? It makes that this RENAME is done in your storage only.? Any user just accessing this shared MDISK at this time will still see the old ABC EXEC.
The RENAME in step 5 causes the mdisk to be updated, both step 4 and 5 are then executed as an atomic event (and that was mentioned in the original message, without the NOUPD there's no such trick)
?
Beware: don't do any other update to disk N between step 4 and 5 or there is a while with only ABC OLDEXEC present on the mdisk.
And, do not ERASE ABC OLDEXEC before you are sure that all users of this shared disk have reACCESSed it.? ?Users that do not reACCESS have for ABC EXEC pointers in storage that point to what now is ABC OLDEXEC on disk.? If you erase if too soon, their pointers point to a place on the mdisk that can be overwritten at any moment
?
--
Kris Buelens
