ADSM-L

Process Preemption

2015-10-04 17:30:27
Subject: Process Preemption
From: Brazner, Bob [mailto:Bob.Brazner AT JCI DOT COM]
To: ADSM-L AT VM.MARIST DOT EDU
To Bob Booth et al,

Back on 6/16/1999, I posted this very issue on adsm-l.  I received a
sympathetic response from Sheelagh Treweek (which I've retrieved from
http://search.adsm.org) and am reprinting here.  All I can say is you are
not alone.

I originally wrote:

We backup our tape pool daily (backup stgppool tapepool copypool).  We have
4
 drives which are almost in the state of constant use with stgpool backups,
 migrations and space reclamation.  If a customer starts a restore when all
the
 drives are in use, ADSM will cancel the stgpool backup in order to obtain
the
 needed drive.  This means we don't get a complete d/r set for that day.  Is
 there a tweak that tells ADSM to cancel other stuff (e.g., space
reclamation or
 migrations) instead of stgpool backups?  Are there other methods to prevent
 dynamic (i.e., customer-initiated) actions from interfering with planned
 production operations?

To which Sheelagh replied:

hi Bob,

 No, presently it is not possible to do what you want!  And if folks
 keep asking then someday we might start to get some of these very
 desirable features.

 Also, "Bazuin, R. (Ronald)" <Ronald.Bazuin AT NL.FORTIS DOT COM> suggested:

 "For that reason whe have 5 drives so 1 drive will always be available
 for restore."

 ...  but sadly if 2 or 3 such restores occur then you still have a
 potential problem here.  The answer is in giving the proper controls
 to the administrator and in this case :

 1) The word pre-empt should mean interrupt and then resume and not
    abort.

 2) It should be possible to partition resources so that the system
    management tasks can be accomplished in a sane manner whilst making
    provision for client activities.

 For information, you can submit (or concur with an existing) DCRs via
 your IBM Account Manager (not sure what you do if you run on non-IBM
 kit?).  It is my understanding that pretty well most suggestions (such
 as these) are most likely to already be on the Requirements Database
 ...

 Regards, Sheelagh
 ------------------------------------------------------------------------
 Sheelagh Treweek                   Email: sheelagh.treweek AT oucs.ox.ac DOT uk
 Oxford University Computing Services           Tel:   +44 (0)1865 273205
 13 Banbury Road, Oxford, OX2 6NN, UK           Fax:   +44 (0)1865 273275
<Prev in Thread] Current Thread [Next in Thread>