Wilm,
On the use of /IGNORE=INTERLOCK, yes it is a problem. It depends on the "luck of the draw". For example:
- user changes password while backup in progress
- batch/print job changes status or attributes while backup is in pogress.
Is the danger theoretical? Yes, and No. For the record, I HAVE SEEN problems occur. Does every backup done with IGNORE=INTERLOCK fail, NO. Is the potential for serious problems there: YES.
What steps you take depend on the potential side effects.
The solution with a third shadow set member works well, but it if you want guarantees, one must quiesce the system for the instant that it takes to disconnect the third shadowset member.
A compromise is to take the BACKUP; and make seperate copies of those files that were interlocked. I am limiting this discussion to system files. If applications are included, check carefully, applications that perform extensive internal cacheing, particularly write-back style, are at a serious potential of confusion if you ignore interlocking.
A valid strategy on a pure system disk is to perform the BACKUP without IGNORE=INTERLOCK, and back up those few files separately with appropriate means.
I hope that the above is helpful.
- Bob Gezelter,
http://www.rlgsc.com
