>> hundred pounds per year.
> 
> You're going to store an entire set of backups on 5 or 10 tapes?  Aren't 
> you backing things up every week, or every day?

They want to keep every monthly backup forever. The other tapes get 
rotated for a year, and then the whole lot get "archived". So we have 
full backups from each month, and then a load of differential backups 
from the last few days of the year. Like, WTF?

>> Interestingly, I worked out that based on the dimensions of an LTO 
>> tape [not sure if this is with or without case] you can store enough 
>> takes in 1 m^2 for 360 years of backups. :^}
> 
> Only if you fill the tapes. And a cubic meter of media safe storage is 
> pretty expensive.

Yeah, but I was thinking that after a year or two we'd have a whole 
*room* full of stuff. Clearly that isn't really the case.

> If you phrase everything as a reasonable question, it's more difficult 
> to get upset at the person asking. (Not impossible, mind; see the "shoot 
> the messenger" syndrome.)

I don't know about you, but I tend to find that if I ask anything or add 
any comments, these are all silently ignored. Because ignoring problems 
makes them go away, doesn't it?

>> I suggested MD5 hashes or something would be a good idea. I even 
>> suggested a procedure for using 'em...
> 
> What's wrong with "comp"?

Does that exist on Windoze?

> Or just a little program to read two files 
> and compare the contents, if that's what they're really worried about?

Yeah, we could do that. MD5 has the nice property that it can be written 
down on a sheet of paper, and easily checked again later. But for this 
particular scenario, a basic file compare would be fine. (We would 
probably have to formally test the correctness of the compare program 
though!)

>> That's the amusing part - there *is* a chart in the document! It just 
>> doesn't make any *sense*. :-/
> 
> Well, ask them to express the chart as a calendar, since you don't 
> understand what it means. Or otherwise ask them what you're confused 
> about. If there's contradictory information in the chart, come up with 
> an example that matches both contradictory elements and ask what the 
> answer is, after pointing out that one element in the chart says yes and 
> the other says no.

The chart *is* a calendar - but it shows only 1 son tape, 1 father tape, 
and 1 grandfather tape, which makes no sense at all. But then, none of 
the parts are labelled, so you have to take guesses at what it's saying...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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