CloudFS vs. ecryptfs vs. encfs vs. Tahoe-LAFS

Zooko O'Whielacronx zooko at
Fri Jun 10 16:52:10 UTC 2011


Hi, folks:

I'm a contributor to the Tahoe-LAFS project ( ),
and Jeff Darcy (whom I have shared technical chat with for many a
year) pointed this thread out to me.

First of all, I'd like to emphasize that GlusterFS and Tahoe-LAFS are
very different beasts. (Jeff probably already knows this, but...)

Tahoe-LAFS is almost more like a "nosql" key-value store or like a
cloud storage system like S3 than like a filesystem. Maybe I shouldn't
have even put the "FS" in its name! But, back when Tahoe-LAFS started,
the words "nosql" and "cloud" had not yet been coined. :-) Also, we
*do* provide a files-and-directories graph structure, unlike most
nosql-ish/cloud-ish things, and we do attempt to layer on a (possibly
very inefficient) POSIX API through the SFTP interface, which is what
Jeff benchmarked.

So, all of this is to say that I'm not surprised if Tahoe-LAFS
performance for filesystem-flavored tasks is much worse than

I am really pleased to see these numbers. Thanks for doing this! I've
been wishing for some measurements like this for a long time.

Could you please give more details about what the workload was? If you
used the SFTP interface, then I assume it consisted of merely
uploading and downloading files, right? Because SFTP doesn't really
support POSIXy things like editing the contents of files in place
AFAIK. "Just uploading and downloading files" is what Tahoe-LAFS has
always been primarily intended for, so if it is this much slower even
for that use case, then I can't place the blame for the slowness on
the POSIX API layer but instead it rests on the core Tahoe-LAFS
protocols themselves.

Also, could you run the same experiment with vanilla GlusterFS sans
all encryption, or with CloudFS with encryption turned off? Those
would be very interesting numbers to see.

I don't know if this fits your API/use cases at all, but a mature and
widely cited benchmark is the Yahoo! Cloud Serving Benchmark. I would
love to see CloudFS compared to some of the ten or so databases tested
by that framework:



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