Re: Finding out which volumes have been backed up

[Peter Lister, Cranfield Computer Centre]

> Whenever _I_ do "vos move", the backup volume gets deleted; having butc query
> the VLDB prior to each volume dump seems redundant (either the volume is
> where it started out, or it's not - in the latter case, there's no .backup
> volume anyway).  I suppose a "lock" on the volume until it's dumped would
> work, but I don't find it essential, and can think of cases where it would
> be annoying.

Whenever *I* do a vos move, the backup is deleted; I immediately recreate it. 
Whenever *balance* does a vos move the same thing happens. I wish vos move 
could be told to recreate the backup automatically in one operation (and for 
that matter recreate a readonly, with a vos addsite at the new partition, vos 
rel and vos remove the old readonly).

I am happy to accept that if I perform an operation which deletes the backup, 
then the volume doesn't get backed up. But given that a vos move will almost 
always (certainly at Cranfield, and I guess elsewhere) be followed by a vos 
backup, I think it entirely reasonable that butc should have another look to 
see if the volume has moved recently, or (the best solution) locate the volume 
shortly before it needs to do the backup, then lock it until it has finished. 
I also hope that if butc finds the volume it wants to be already locked, it 
will try again later and go on to the next.

I do not regard locking every volume which is about to be dumped as an optimal 
solution, and never intended to give that impression. It is a horrible, yucky 
idea, but given that this is how butc behaves at the moment, it is the only 
behaviour *consistent* with a reliable backup. It is this lack of consistency 
which has already caused problems. If I am faced with a rapidly filling 
partition halfway through a full dump, what do I do? 

And as with all behaviour changes, make it switchable. If you don't see the 
need, Pat, fine, don't use this facility. I don't want to tread on your toes; 
I trust you don't want to tread on mine.
 
Peter Lister                             Email: [EMAIL PROTECTED]
Computer Centre, Cranfield University    Voice: +44 234 754200 ext 2828
Cranfield, Bedfordshire MK43 0AL UK        Fax: +44 234 750875
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