[Info-vax] ODS-5 to ODS-2 Data Migration

[Zane H. Healy]

Michael Moroney <moroney at world.std.spaamtrap.com> wrote:
> "Zane H. Healy" <healyzh at avanthar.avanthar.com> writes:
> 
>>Bob Gezelter <gezelter at rlgsc.com> wrote:
> 
> Beware, there was a change to ODS-2 that isn't compatible with
> VMS V7.2 and earlier (or was it V7.1 and earlier?). There's no version
> bump with this change, either.  Older versions of VMS won't be able to
> mount these disks.  The biggest change was the size of the allocation
> bitmap, from 255 blocks (thus a maximum of 1+ million clusters on a disk)
> to 64K blocks, but there are some other bits that were defined with the
> change (such as for INIT /LIMIT or INIT /SIZE).
> 
> Best thing to do is if you want to access disks from older versions is to
> initialize the disks on those older versions, but disks inited on newer
> versions will work if you don't specify the newer features and the cluster
> size doesn't create an oversized bitmap.

Thanks, I wasn't aware of that change.  Here at home, I'm currently on
5.5-2, 7.3 and 8.3 (Alpha).  The 5.5-2 system is pretty much seperate from
the cluster, and is used for older software (mainly to play DND).

Zane