Category: shell

Wireguard on Lightsail gone Ship-Wrecked

For a long time now I run an AWS Lightsail VPS serving as a wireguard gateway to my home server. Since recently connecting to the Lightsail instance via wireguard is no longer possible.
When I took a look with SSH I got

$> sudo wg-quick up wg0
[#] ip link add wg0 type wireguard
RTNETLINK answers: Operation not supported
Unable to access interface: Protocol not supported
[#] ip link delete dev wg0
Cannot find device "wg0"

To be sure I updated all packages, but the problem still persisted.
The port used by wireguard had not changed and still was accessible according to the network settings of Lightsail.
What change in the Lightsail VPS or network settings could cause an issue like this? It literally just stopped working over night.

Undelete Files with SnapRAID

Today I accidentally deleted a whole folder of important documents on my OpenMediaVault(OMV) NAS, while doing some cleaning up.
Of course I would have a backup of the folder on an external hard-drive, but this was the perfect opportunity to test SnapRAID.

Process Control in a Linux Shell

Working on the command line in a Linux shell can be tricky at times. A frequent source of frustration is that tasks which are trivial with a graphical desktop environment can be seemingly much more difficult to achieve on the command line. For example switching between multiple running applications only requires one or two mouse clicks on a graphical desktop, but demands more arcane knowledge to do it on the command line.

Upgrading Fedora

I have an old T61 notebook with Fedora 23. Since this distribution release is quite outdated I upgraded to the latest release version (27) this weekend. This can be done quite easily with the dnf-plugin-system-upgrade package.

$ sudo dnf install dnf-plugin-system-upgrade

$ sudo dnf system-upgrade download –refresh –releasever=27

$ sudo dnf system-upgrade reboot

If all goes well Fedora will upgrade to release 27 after the next reboot. I had to uninstall a few packages first, for which dnf complained about dependency conflicts.

For more details check out the Fedora Wiki.

Sneaky Serial Port

Tried out serial communication b/w PC (Windows 7 using hterm) and notebook (Fedora 23 using bash+stty).

Could get data from notebook to PC but not vice versa. Reading from /dev/ttyUSB0 just would not show any received data.

Tried out all combinations of parity bits, stop bits.

Turns out all data arrived but LF was missing, so nothing was displayed in the shell….

That’s one wasted afternoon.

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