I have been using Unison to sync directories on my N900 & a external hard drive on an Ubuntu desktop.

Rather than install Unison on the N900, Unison is installed only on the Ubuntu machine, & the N900 is connected in Mass Storage mode via USB. The N900 directory to be synced is discovered as the local machine's /media/1xx1-xxx1/whatever directory, & Unison easily works.

Is it possible when I connect the Ubuntu machine to the N990 over wifi ssh/sftp to find or write that path as a local path on the Ubuntu machine?

You want to sync files from the N900 to your external drive? You could just use rsync+alarmed (for scheduling) to achieve that.

The versions of Unison must be compatible to have it working. Make sure ssh is started on the N900.
The command should be something like this to test if a connection can get establishedRemove -testserver if the command is successfull.

Why not install unison on the N900? That way you can sync remotely too. If you unpack unison 2.32 armel deb from debian to your home directory and just run it from xterm it works like a charm. Otherwise maybe you can use sshfs to mount a local path to an ssh location but I'm not sure that works.

I was trying to get around installing Unison on the N900, to keep things minimal.

Thanks for the tip on sshfs. It's pretty much the setup I was looking for, & it seems to have worked well. Or maybe not - I created a directory on the N900s SDcard with sshfs from my computer at home, & now it seems I don't have write permissions to it.

unison is not running on the N900 as a daemon, it is just being invoked when the computer connects. So the only overhead is the disk space the unison binary takes up in home. (a few kb's)

about the permission thing check your mount command for reaad-write

Where did you get the version of unison you're running on the N900?

This is known issue, if you create a directory or file on rootfs or opt partition (not fat32 MyDocs or mmc card), you need to do it using the same user with login=="user" and same uid (as far as i remember it's "1000") OR with user from the same group (this solution is easier) - see http://talk.maemo.org/showpost.php?p...26&postcount=9 for information how to do it.

edit: did you login via ssh as user or as root? when using sshfs, you should use "user", not "root".

This http://packages.debian.org/squeeze/a...nison/download

don't try to install. just unpack the binary to /home.

if you need to run unison from your computer you'll need to create a symlink in /usr/bin. I always run it on the N900 which accesses the pc via ssh so just the binary in /home does the job.

Although the solution from qwazix is probably better, you can connect/mount ssh locations natively in ubuntu's file explorer (connect to server), and bookmark them for future use.

Then, if you assume your computer is secure, you can go for a key based login to the N900 (and disable password login for good measure). That way, N900 folders are one click away from your desktop, all wirelessly.