Hi Farren,

the main reason to backup data is to be prepared to restore them.
If you want to make your restore faster, collocation is a good option.
In an Enviroment without collocation, data for one client will spread over
all tapes in the tapepool.
At restore TSM will do this for every tape:
Mount tape, wind forward to data location, read data, rewind tape, unmount
tape.
With collocation enabled you will reduce the number of tape mounts, this
will
save a reasonable amount of restore time.
If you backup incremental only the data needed for restore are not
continous on tape and this will happen at restore:
Mount tape, wind forward to data location, read data, wind forward to next
data location, read data ... (doing this for every little piece of data)
..., rewind tape, unmount tape.
..., rewind tape, unmount tape.
Make an extra selective backup from time to time to avoid/reduce this. It
will make your restore even faster.

Greetings
Jan Möwe





                                                                                
                                                     
                    Farren Minns                                                
                                                     
                    <fminns@WILEY        An:     ADSM-L AT VM.MARIST DOT EDU    
                                                            
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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?
2)   Secondly, can someone tell me a good, clean, simple way of achieving
only collocating certain clients.
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).

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