After upgrading to the latest DSM (4.0-2228) version, I’ve found out that I was unable to login as the user root by connecting through ssh.
Enabling and disabling ssh on the control panel and changing the admin password on the Synology Web Interface had no effect.
I even tried to use the known password for the root user to logon, but that also failed.
So the solution?
- Enable telnet on the DSM Control Panel.
- Connect to the NAS using Telnet and login as root. The password should be the same password used by the web interface admin user. If not, change again the admin password.
- Execute the following command synouser –setpwd root password_same_as_admin_or_not
(Note: is dash dash for the setpwd command line option)
- Trying now to ssh as root it should succeed with the password gave in the above command
- Disable telnet on the DSM Control Panel
EDIT: For those that have the issue after upgrading to DSM 6.0 ( I haven’t yet upgraded, I always wait at least a month…), the solution is a follow (Thanks to the comment below of ubergard). Please note that I haven’t test it.
After getting the DSM 6.0 upgrade, I’ve become unable to login as root using SSH, even though I’ve been able to do it before the upgrade (DSM 5.5 or something like that).
1. SSH to machine as admin user.
2. Enter command “sudo -s” and providing admin password.
3. Enter command “synouser -–setpw root “.
Now I’m able to logon as root using SSH again, and I didn’t have to mess with telnet.