[Info-vax] Reclaim disk space for a 3PAR Storage Box

[abrsvc]

On Monday, August 30, 2021 at 8:19:54 AM UTC-4, Simon Clubley wrote:
> On 2021-08-30, Volker Halle <volker... at hotmail.com> wrote: 
> >> My problem is that for big disks (800GB) with a low used space, we create thousands and thousands of files and the DELETE/ERASE takes days. 
> > 
> > Bruno, 
> > 
> > on those big disks, is DELETE/ERASE the problem or the fact, that you have to delete 'thousands and thousands' of (small) file in ONE directory ? How big is the .DIR file after you've created those temporary 10 MB files ? Would it help, to DELETE/ERASE those files in reverse order, i.e. highest version number first ? This would reduce the shuffling of entries in the directory. 
> >
> If he has a range of filenames, version numbers will not be the only issue 
> here, but also the ordering of the filenames in the directory file. 
> 
> He needs to delete files in reverse name order _and_ for a given filename 
> needs to delete those files in reverse version number order as you say above. 
> 
> Hard to believe that this is still a problem on VMS in 2021. 
> 
> Simon. 
> 
> -- 
> Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP 
> Walking destinations on a map are further away than they appear.
I would not consider it a "problem" just the way that directory files work.  If proper directory maintenance is performed on a regular basis, this is not a problem.  Only mass deletions show the "problem".  Knowing how things work often present more efficient ways to perform operations. Here for mass deletions, reverse order is more efficient.  Is "normal order" a problem, NO, but it will take a while.

Think of this as a similar issue to column order referencing of array elements vs. row order.  Depending upon how arrays are stored, you could either efficiently make use of sequential memory references or not.  Problem NO for either case, just one way is more efficient.

Dan