Reuben Thomas <rrt <at> sc3d.org>
2012-12-04 15:36:13 GMT
I'm trying to use an SSHFS mount for backing up a large amount of data. I
use Unison for my backups:
Unison essentially uses the rsync algorithm. It's very stable and I've used
it for years successfully. Normally it uses ssh directly (like rsync), but
I am trying to use it with sshfs as I want to use it to tunnel an encrypted
file system (such as s3ql: http://code.google.com/p/s3ql/).
I have used Unison with a FUSE file system successfully in the past
(plpfuse: http://plptools.sourceforge.net/, which I wrote myself!).
I am finding two problems using Unison over SSHFS: first, data transfer is
very slow: my ADSL uplink usually transfers upstream at about 100kb/s, but
with Unison over sshfs seems to run about 1kb/s. Secondly, after running
for a while (usually some hours), it seems to get stuck somewhere in kernel
Of course, I am not asking here for a solution to problems involving 3rd
party software, but I was wondering if anyone could give me tips on
tracking down the source of the problems in this case. So far, I have
discovered is that working just with S3QL, which also uses FUSE, mounting a
local directory, unison is quite happy, and I get the same problem of
freezing when using sshfs on its own as when using sshfs+S3QL, so the
problem appears to be confined to the interaction of Unison and sshfs.
I'm using sshfs 2.4, and Unison 2.40.65.