[tahoe-dev] How many servers can fail?

[Dirk Loss]

On 26.10.11 00:53, Brian Warner wrote:

> So 1.7.0 changed the old "shares of happiness" into a more accurate (but
> more confusing) "servers of happiness" (but unfortunately kept the old
> name). It also overloaded what "k" means. So now you set "H" to be the
> size of a "target set". The uploader makes sure that any "k"-sized
> subset of this target will have enough shares to recover the file. That
> means that H and k are counting *servers* now. (N and k still control
> encoding as usual, so k also counts shares, but share *placement* is
> constrained by H and k). The uploader refuses to succeed unless it can
> get sufficient diversity, where H and k define what "sufficient" means.

Thank you very much for your elaborate reply. I am still trying to
figure out how this all works together, but your explanation helped a
lot in understanding the meaning of N, H and k.

Best regards,
Dirk