When your DHCP client has lease renewal issues, Sendmail may be at fault

On one of our VPS instances, I noticed some seriously erratic behavior with the DHCP client taking a long time to renew its leases when the machine was booting up, or failing to renew at all.

It took some time before I noticed this output from dhclient:

/sbin/dhclient-script: 28: .: Can't open /usr/share/sendmail/dynamic

This didn’t make any sense as we never have and never will install sendmail on any VPS. So using apt, I was able to see that one or more of the sendmail packages had “incomplete” status (displayed as ‘c’ in aptitude if you’re using that), i.e. it was not installed but some configuration files remain. After purging those packages, dhclient had no problems whatsoever in renewing the leases.

Who knew sendmail could even trash DHCP 🙂

 

 

Fixing some keyboard shortcuts in XFCE (Ctrl+F5 and Ctrl+Alt+T)

Old habits die hard, or something like that 🙂 Cloning one of my Ubuntu Desktop set-ups to a VirtualBox environment, I switched to using XFCE4 for my desktop (“xubuntu”). This works very well and the transition is minor. Most of the applications I use work very well in both Gnome and XFCE, apart from two keyboard shortcuts I use very often.

Ctrl+F5

Ctrl+F5 to force a page/cache re-load in many browsers is attached to workspace switching in XFCE. I only have four workspaces (and rarely use more than two), so I don’t need this shortcut.

To make Ctrl+F5 work as expected (for me) in the browsers, simply go to the Application Menu or “Start” menu (upper left corner in XFCE by default), scroll down to Settings and choose “Settings Manager”. In there, select “Window Manager”. Move to the “Keyboard” tab and scroll the list until you find something with Ctrl+F5 in the “shortcut” column. For me, this was defined as “Woprkspace 5”. Choose to Clear the shortcut when the selection bar is in the right place. Click “Close” and voila, your Ctrl+F5 reload shortcut now works again.

Ctrl+Alt+T

I don’t know how people survive without a shortcut for opening a Terminal, but I guess they do. From Gnome, I’ve been used to being able to open up a new Terminal quickly by pressing Ctrl+Alt+T. This does not work in XFCE by default, but is easily remedied using a method similar to that of Ctrl+F5 above.

To assign Ctrl+Alt+T to open a new Terminal in XFCE, go to the Application Menu or “Start” menu (same upper left corner as before), scroll down to Settings and choose “Settings Manager”. In there, select “Keyboard”. Move to the “Application Shortcuts” tab and click the “Add” button. Now specify the application you want to open for your shortcut, in my case xfce4-terminal, and click OK. XFCE will now ask you for the desired keyboard shortcut, in my case Ctrl+Alt+T. And we’re done!

If you want to open the “preferred application” for “Terminal” in XFCE, instead of a specific terminal application, go and lookup how to use “exo-open”, which is a way to say “Please open my preferred application for …” in XFCE.

Enjoy your shortcuts!