How to project usage.

[Stacey]

I have been asked to project avalable space on servers for next year for each
month. I know how much space is free for each drive for each of the last five
months.

Example of what I have in MB:


Dates 5/05 6/05 7/05 8/05 9/05 10/05
Server A C:\ 256 248 200 175 177 130
D:\ 1350 1220 1163 1000 950 937


Any sugestions would be great. I have to do this for over 350 servers with
between 2 to 4 drives each.


Thanks

 

[Ron Rosenfeld]

I have been asked to project avalable space on servers for next year for each
month. I know how much space is free for each drive for each of the last five
months.

Example of what I have in MB:


Dates 5/05 6/05 7/05 8/05 9/05 10/05
Server A C:\ 256 248 200 175 177 130
D:\ 1350 1220 1163 1000 950 937


Any sugestions would be great. I have to do this for over 350 servers with
between 2 to 4 drives each.


Thanks

Not knowing how the usage is growing, any forecasts would be real guesses.
It's hard to tell whether a straight linear regression or an exponential fit
would be a better predictor. However, the former would be more conservative,
in that it would result in your increasing drive size sooner.

To do that, use the FORECAST worksheet function.

If your table above is in A1:G3 (with the dates and data in B1:G3) then:

H1:L1 11/05 12/05 1/06 2/06 3/06

H2: =FORECAST(H$1,$B2:$G2,$B$1:$G$1)

Copy/Drag down across to L2.

Then select H2:L2 and copy/drag down to H3:L3

If your table is in another area on your worksheet, be sure to get the mixed
relative/absolute references correct, or else they won't adjust properly when
you drag them to the new cells.


--ron