NO. I don't think so. The offsite pool should not be collocated unless
you have a service level agreement that says a file that's backed up has
its copy sent offsite withing 12-24 hours. But if you need to do that
then why isn't the tape drive remotely IN the offsite vault(like a
bank's?)???????????????
I think collocation of the ONSITE pool is very important for large or
small users. Who wants to wait around for hundreds of tapes to be mounted
over 2, 4, 6 or evan a 'measly' 8 drives? :-)
My setup is: 1100 users, 435 cells in a 3494 (1 ... now 2 frames) 4 3590s
(2 originally). I maintain a collocated onsite of all but about 20 tapes.
There's a comparable amount of offsite tapes. When an offsite tape goes
to FULL its pulled and sent to ARCUS vaulting with a matching DBS. I only
allow 1 OFFSITE tape to be mounted and written on at a time.
Onsite tapes: I try to have nothing but FILLING tapes at 50% or lower.
This is ideal and never happens. Best I can achieve is 1/3 full
and 2/3 FILLING and at 45%. (not counting pending tapes)
I have a perl program that adds 1 or 2 scratch tapes everytime an onsite
is reclamated. I figure adding 2 for every one, when its possible, helps
'tease' the larger users off to their own tape and ensures that everyone
'migrates' to their one and only tape as time goes by.
The twenty scratch tapes are used on weekends to reclamate the offsite.
I only maintain at most 6 DB backups in the box but 9 DBS are offsite.
We have a two week rotation on offsite so at any one time there's two sets
of 20-35 pending (empty) tapes waiting to come back.
cheers ! ... joe.f.
Joseph A Faracchio, Systems Programmer, UC Berkeley
Private mail on any topic should be directed to :
joef AT socrates.berkeley DOT edu
(510)642-7638 (w) (209)483-JOEF (M)
5633
On Mon, 19 Nov 2001, Farren Minns wrote:
> Hi
>
> Ok, well thanks to everyone for the info you have given me, but I do still
> have one burning question.
>
> As we have just one copypool, Is it really necessary to collocate it? We
> have a reuse delay period of 5 days, so as we send about 25 off a day, we
> end up with loads of pending volumes, but far too few in the way of scratch
> volumes (I have to keep costs down as much as possible).
>
> Thanks again for your help
>
> Farren :)
>
>
>
>
>
>
> Fred Johanson <fred AT MIDWAY.UCHICAGO DOT EDU>@VM.MARIST.EDU> on 19/11/2001
> 14:51:59
>
> Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
>
> Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
>
>
> To: ADSM-L AT VM.MARIST DOT EDU
> cc:
> Subject: Re: Help please with collocation
>
>
> At 11:34 AM 11/19/2001 +0000, you wrote:
> >Hello again TSMers
> >
> >I have some another questions, this time regarding collocation.
> >
> >At present we are backing up 21 client nodes and have a backup pool made
> up
> >of DISKPOOL and TAPEPOOL. Then we have our off-site volumes, imaginatively
> >entitled COPYPOOL. I am thinking that we do not necessarily need to use
> >collocation for all of our nodes; maybe just for five or six of our more
> >important ones (we do backup sets for these as well).
> >
> >The questions are as follows:-
> >
> >1) What are peoples thoughts on collocation in the first place. Is it
> >generally a good idea? Any thoughts really?
>
> One of my machines has 950 clients, all under some local administration. A
> graduate division lost their budget folder two weeks ago and are still
> working on recovering it because it's spread over 50-75 tapes. But we're
> still working on the politics of collocation for these users. My other
> machine has 850 clients, mostly under central control, so I collocate
> everything but desktops. Critical restores go much quicker, but I have to
> spend at least 8 hours a week husbanding a too small scratchpool.
>
> >2) Secondly, can someone tell me a good, clean, simple way of achieving
> >only collocating certain clients.
>
> I use multiple domains with diskpools that go to tapepools that do or do
> not collocate.
>
> >3) Also, baring in mind that at present, we back up all clients to one
> >COPYPOOL, what would be the implications of a) moving some clients to a
> new
> >backup COPYPOOL (what happens to all the data currently stored on the
> >original COPYPOOL and b) turning off collocation for the original COPYPOOL
> >(i.e. would this lead to a very long reclamation run).
>
> Everything goes to a single copypool. If I have to restore a volume, TSM
> is bright enough to figure things out.
>
>
> >There is probably a lot more inf. that I should have included here, but I
> >am relatively new and probably don't know the questions to ask.
> >
> >Thanks again and I look forward to any help you can all give me.
> >
> >All the best
> >
> >Farren Minns
>
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