Re: VMS731_DISMOU-V0100 - What are the issues?

From: Mark Berryman (Mark.Berryman_at_Mvb.Saic.Com)
Date: 10/03/03 

Date: Thu, 02 Oct 2003 15:08:52 -0700

norm.raphael@metso.com wrote:
>
>
> If one patches to get the retro behavior, what would happen at V7.3-2?
>
> But more to the point, why would one want one or the other behavior?
>
> -Norm
> ------------
> TITLE: OpenVMS VMS731_DISMOU-V0100 Alpha V7.3-1 ECO Summary
>
> System/Cluster Reboot Necessary: No
>
> Installation Rating: INSTALL_3 :
> To be installed by customers experiencing the problems
> corrected.
>
> PROBLEMS ADDRESSED IN THIS KIT
>
> New problems addressed in the VMS731_DISMOU-V0100 kit
>
> o VMS731_DISMOU-V0100.RNO
>
> A change made for OpenVMS V7.3-1 to delete write bitmaps
> when a virtual unit is dismounted. The purpose of the
> change was to return memory to the system. However, some
> customers depend on the master bitmap remaining, even if
> the virtual unit is dimounted.
>
> Since customers who wish to have the bitmaps deleted can
> manually delete them, this change removes the code that
> deletes the bitmap and reverts functionality to the
> pre-V7.3-1 state. Customers that want to delete any
> unwanted bitmaps can do so via SHOW BITMAP and DELETE
> BITMAP commands. These commands have been part of
> OpenVMS since V7.2-2.
>
> Images Affected:[SYSLIB]DISMNTSHR.EXE
>

If the bitmap survives the removal of the virtual unit then it becomes
possible to dismount shadow sets on one member of a cluster that is
contributing members to the shadow sets, reboot that member, then
remount the shadow sets on that member using a minicopy rather than a
full copy. If the bitmap is deleted as soon as the virtual unit (DSAn)
is dismounted, then that cluster member must do full shadow copies when
it reboots and remounts the shadow sets.

I was one of the customers who asked for this.

Mark Berryman

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