Short takes: SSH, custom ports, root and Synology NASs

Posted on By Mark Wilson
This content is 7 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

This blog has been much maligned of late… I’d like to get more time to write and I have literally hundreds of part-written posts, some of which are now just a collection of links for me to unpick…

In the meantime, a couple of snippets that may be useless, or may help someone one day…

Using SSH with a custom port number

My Synology NAS complains about poor security if I leave SSH enabled on port 22. It’s fine if I change it to another port though (security by obscurity!). Connecting then needs a bit more work as it’s ssh user@ipaddress -p portnumber (found via the askubuntu forums)

Logging on to a Synology NAS from SSH as root

On a related topic, I recently needed to SSH to my NAS as root (not admin). ssh root@ipaddress -p portnumber wasn’t authenticating correctly and then I found Synology’s advice on how to login to DSM with root permission via SSH/Telnet. It seems I have to first log on as admin, then sudo -i to elevate to root.

Synology Hyper Backup and DSM update failures

Posted on By Mark Wilson
This content is 7 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

I have a Synology DS916+ NAS and, for the 9 months or so, I’ve been using it to back up my photos to Microsoft Azure. I’ve realised that they are being backed up in a format that’s unique to Synology’s Hyper Backup program, so I should probably see if there is an alternative that backs up the files in their native format but, more worryingly, this afternoon I noticed that backups had been failing for a few days. The logs weren’t much help (no detailed information) and a search on the ‘net didn’t turn much up either. For reference, this was the (very high level) information in the logs when viewed in the Hyper Backup GUI:

Information 2017/07/08 03:00:02 SYSTEM [Azure Blob] [Backup Photos to Microsoft Azure] Backup task started.
Error 2017/07/08 03:00:33 SYSTEM [Azure Blob] [Backup Photos to Microsoft Azure] Exception occured while backing up data.
Error 2017/07/08 03:00:36 SYSTEM [Azure Blob] [Backup Photos to Microsoft Azure] Failed to backup data.
Error 2017/07/08 03:00:36 SYSTEM [Azure Blob] [Backup Photos to Microsoft Azure] Failed to run backup task.

(Since then, I’ve found how to view detailed backup logs on a Synology NAS, thanks to a blog post by Jonathan Mumm, though in this case, the logs didn’t shine much of a light on the problem for me.)

I wondered if there were any DSM updates available that might fix things but, when I checked for updates, I got a message to say “Insufficient capacity for update. The system partition requires at least 400MB”. Googling suggested lots of manual file deletion and I was sure this was just a buildup of temp files (maybe to do with the failed backup), so I decided to reboot. After all, what do you do when a computer isn’t working as expected? Turn it off and on again!

After rebooting, attempts to update no longer produced an error (simply confirming that I’m up-to-date with DSM 6.1.2-15132) and the backup is now running nicely (it will take a few hours to complete as I added a few months’ worth of iPhone photos to the NAS earlier in the week, around about the time the backups started failing…)