New user, sftp issues

Getting Help
1

Hello,

I’m trying out restic with my Synology NAS. It looks like the easiest way to set things up is to use SFTP. After setting up password-less login, my user has ownership and write permissions on /volume1/backups/restic-dest, but running restic init fails with

$ restic -r sftp:me@server:/volume1/backups/restic-dest/ init
create backend at sftp:me@server:/volume1/backups/restic-dest/ failed: mkdirAll(/volume1/backups/restic-dest/index): unable to create directories: mkdirAll(/volume1/backups/restic-dest): unable to create directories: mkdirAll(/volume1/backups): unable to create directories: mkdirAll(/volume1): unable to create directories: <nil>, sftp: "Permission denied" (SSH_FX_PERMISSION_DENIED), file does not exist, file does not exist, file does not exist

Looks like a permissions problem, but if I run

$ ssh me@server "mkdir /volume1/backups/restic-dest/index"

Then I can create the directory no problem.

Thanks for any help.

2

I remember that someone somewhere wrote that the sftp paths for Synology NAS are not the same as the paths you see after login with ssh.

You can use sftp me@server and then pwd to get the directory exposed via sftp, that tell you what the directory needs to be.

Please report back!

3

Confirmed on my Synology.

SSH puts you in your home directory but allows you access to the rest of the filesystem

$ ssh p4.lan
X11 forwarding request failed on channel 0
wscott@p4:~$ pwd
/var/services/homes/wscott
wscott@p4:~$ ls -d /volume1/crashplan
/volume1/crashplan

And sftp also puts you in your home directory, but in a chroot environment where that directory is at the root and you can’t leave.

$ sftp p4.lan
Connected to p4.lan.
sftp> pwd
Remote working directory: /
sftp> cd /volume1
Couldn't stat remote file: No such file or directory
4

That did it, shared volumes (and nothing else) are exposed under sftp. Thanks!

5

This specific Synology NAS behavior is now documented in the FAQ.