Re: [freehaven-dev] meeting sunday 2pm

[Todd Kamin <tkamin@MIT.EDU>]

I've got a question about how the whole buddy share idea relates to the idea of
splitting files into shares.  I might be missing something here, but it seems to
me we have added excess redundancy and complexity by including both these ideas.

Why do we even need buddy shares?  If some k shares of N total shares of a file
are needed to reconstruct it, then N-k shares can be lost over the lifetime of a
file without affecting the system's ability to reconstruct the file.  If the
servnet is sufficiently evil so that more than N-k shares get lost over the
lifetime of a file, then the servnet itself shouldn't be probably trusted with
data at all.  In this case where many of the servers are evil, having a buddy
might provide a little more robustness, but it won't ensure that files are not
lost or that parts of files are not lost.  We don't want to burden the
good servers with endlessly spawning copies of shares.  And, best of all, we
won't have to deal with designing a good buddy share system.

Curious,
Todd