Onbar's Handling of "Empty" Chunks

How does onbar handle "empty" chunk files during backup and (especially) restore? Is it intelligent enough to determine that a chunk contains no data at all and can be handled differently (perhaps more efficiently?) than one that contains user data? Or is this an irrelevant consideration, and it just handles the entire chunk in the same way regardless of its content? We're in the process of moving physical to virtual hosts and need to determine speediest way to migrate our boxes: shutdown Informix, take a backup of the entire host, then restore it all using the filesystem restore utility; or take an onbar archive, backup only non-chunk files, then restore filesystems followed by an onbar restore. Using IDS 10.00.FC6 on RHEL4/2.6.9 and Tivoli Storage Manager

On Aug 26, 11:12 am, red_valsen <red_val...@yahoo.com> wrote: > How does onbar handle "empty" chunk files during backup and > (especially) restore?  Is it intelligent enough to determine that a > chunk contains no data at all and can be handled differently (perhaps > more efficiently?)  than one that contains user data?  Or is this an > irrelevant consideration, and it just handles the entire chunk in the > same way regardless of its content? > > We're in the process of moving physical to virtual hosts and need to > determine speediest way to migrate our boxes: shutdown Informix, take > a backup of the entire host, then restore it all using the filesystem > restore utility; or take an onbar archive, backup only non-chunk > files, then restore filesystems followed by an onbar restore. > > Using IDS 10.00.FC6 on RHEL4/2.6.9 and Tivoli Storage Manager Onbar only backed up pages that have been allocated to a tables extents. So if the pages are free in onstat -d output, then they are not allocated to any table's extent, so those pages would be ignored. Jacques Renaut IBM Informix Advanced Support APD Team