Re: srfs - a new file system.

Nir Tzachar
2003-10-23T07:48:50Z

hi there.

> That's annoying when >50% of your servers were unavailable for a period
> of time, because all recent changes will be lost when connectivity is
> restored.

well, if u want a _full_ self stabilizing file system, you cannot behave
any other way. When you have a self stabilizing algorithm, you __have__ to
operate under the assumption that transient errors can and will happen.
so, a cosmic ray can hit N out of your 2N+1 hosts, and corrupt the data
they hold. its very slim, but you have to take these kind of errors into
account to prove the correctness of the algorithm.

> Where in the world did you get the idea that Coda has a main server that
> pushes out modifications? That is so wrong, I don't even know where to
> begin.
ur right, what i described was more like AFS, but you got my point...

> Coda also uses a global namespace that's pretty normal for distributed
> filesystems (AFS/DFS).
well, i was not talking about a global name space. surely u must have one,
otherwise things will get though...
what i meant is, data is replicated at two levels: first, the meta data
(file attributes) is replicated, and the actual data will only get
replicated upon access.

to surmise:
At no time we set srfs to be "better" than CODA.

Our design was aimed to be "close" to CODA, but our emphasis was
self-stabilization, minimal dependency on a single point of failure, and
trust no one (either a central mamanger or stored information).
from here came all our of our design.

cheers.
--
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nir.