I don't want to disagree with the 'large enough for 1 nights dump'
rule of thumb but that's just it: its a rule of thumb.
I thinks in terms of utilizing resources to the 100% level.
(except that there needs to be breathing room for things like restores)
First off:
GET A COMMITTMENT from those MVS SYS Admins or better their manager to
cooperate.
Boy! Once you give up some resources (especially disk space) you'll never
see it again until you convince an MVS Prog's manager that it needs to be
returned!!!!! :-) :-)
Another commmitment to get is tape access and use. With less disk space
you're gonna need more tape access. (you may want to argue about how you
can use the tape drives when they arent' if you had all the disk space
intact if they too do backups of the MVS system and tie up the drives)
I disagee somewhat with the one nights dump in that that assumes you only
want to use the tape drives afterwards and limitedly.
I target a more "rolling" schedule where I do diskpool to copypool
frequently and then a little migration every hour or so in the hopes of
not migrating data that's not already copied to copypool. But then my
environment is 24hour pc and mac backups and restores.
So what I'm trying to say is: think in terms of 24 hour as a resource
and think about the other resources and how all can be used together.
... joe.f.
Joseph A Faracchio, Systems Programmer, UC Berkeley
On Tue, 24 Oct 2000, Gerard M Hanway wrote:
> I look after the companies TSM environment. Approx 700 servers back up an
> average of 60-70gb per night. The ADSM server runs on OS/390 with 500 OS/2 and
> 200 NT clients. I have 2 primary disk pools, one of 45GB for the NT
> servers(colocated) and one of 4GB for the OS/2 servers(non colocated). HIMIG is
> set to 80% on the large pool and usually results is migration starting between 2
> and 3am each morning and completing around 9am.
>
> However the storage people have just been in touch wanting to know what I am
> doing with so much disc in the large pool. Basically they want 30gb back leaving
> leaving me with just 15gb. I suspect that things should continue to work just
> with migration kicking it a lot earlier however I would welcome opinions.
>
> Is there a recommended ratio of disk pool size to amount of data backed up. What
> ratio do most people use. Are there quantifable performance impacts in running
> migration at the same time as backups. I do know from experience that with
> migration starting significantly earlier I can expect a lot of additional tape
> mounts. But it might be argued so what.
> Are there any other gotcha's
>
> Gerard
>
>
>
>
> **********************************************************************
> This document is strictly confidential and is intended for use by
> the addressee unless otherwise indicated.
>
> Allied Irish Banks
> **********************************************************************
>
