Re: db space required for multiple versions, etc
1996-01-22 15:33:20
Greg Tevis wrote, in part...
> The adsm server database requires the same amount of db space to save
> each extra (inactive) version of a file as it does for the active
> version. So the amount of db space required is (almost) proportional to
> the number of versions kept...(further discussions below)
>
> db space (for backup) = v*n*A + K
>
> where v = # of versions kept
> n = # of files backed up to server
> A = db space req'd for each db entry..varies with filenames, ACLs, etc
> typically around 500 bytes.
...
This grossly overestimates database requirement for all but one of our
100 adsm client nodes. I mentioned in a previous article that 2% of my
PC files change per day. But only 10% change each month and less than
20% change each year. So for my PC, the first version requires v*n*A,
but the 2nd requires v*n*A*0.2 and other versions *less* than that.
Greg's numbers make it sound like it's a big deal to increase the
number of inactive files held; it may not be. Your milage may vary :-)
regards,
wayne
Wayne T. Smith
Systems Group -- CAPS internet: wts AT maine.maine DOT edu
University of Maine System BITNET/CREN: WTS@MAINE
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