Here's yet another very useful GNOME Shell extension which serves as a replacement for an old Gnome Panel applet: "Gnome Shell System Monitor Applet".
"Gnome Shell System Monitor" extension displays the RAM, swap and CPU usage on the Gnome Shell top bar (apparently that's how it's called although I tend to call it the 'top panel'). The values are displayed in percentages but when clicked, you can see the actual values and you can also turn off/on the items that are displayed on the top bar:
Update: the extension can now also display network upload / download speed:
The extension is a bit more difficult to install then most other GNOME Shell extensions. If you've installed GNOME 3 in Ubuntu from a PPA, use Arch Linux or Fedora 15, all you have to do is copy/paste the commands below - but please note that I've only tested it in Fedora 15.
For Ubuntu and Fedora, firstly install the dependencies:
- Ubuntu
sudo apt-get install python-gobject libgtop2-7 git-core gir1.2-gtop-2.0
- Fedora:
sudo yum install pygobject2 libgtop2 git
Then, to set up the GNOME Shell System Monitor extension, run the commands below (for any GNOME Shell version 3.0 or 3.2):
rm -rf ~/git_projects #just in case
mkdir ~/git_projects && cd ~/git_projects
git clone git://github.com/paradoxxxzero/gnome-shell-system-monitor-applet.git
Only GNOME 3.0.x, now run the following commands:
cd gnome-shell-system-monitor-applet
git checkout gnome-3.0
cd -
Now again for any GNOME Shell version (3.0 or 3.2):mkdir -p ~/.local/share/gnome-shell/extensions
cd ~/.local/share/gnome-shell/extensions
ln -s ~/git_projects/gnome-shell-system-monitor-applet/system-monitor@paradoxxx.zero.gmail.com
sudo mkdir -p /usr/local/share/glib-2.0/schemas
sudo cp ~/git_projects/gnome-shell-system-monitor-applet/org.gnome.shell.extensions.system-monitor.gschema.xml /usr/local/share/glib-2.0/schemas
sudo glib-compile-schemas /usr/local/share/glib-2.0/schemas
sudo cp ~/git_projects/gnome-shell-system-monitor-applet/system-monitor-applet-config.py /usr/local/bin/system-monitor-applet-config
And finally, reload GNOME Shell (ALT + F2 and enter "r" or log out and log back in). Also, make sure the extension is enabled by using GNOME Tweak Tool (available in the repos).
Update June 6: I've updated the installation instructions above for the latest version. See this post for what's new in the latest System Monitor Shell extension.
However, if you've compiled Gnome Shell using jhbuild, those instructions won't work. I've tried replacing the paths with my jhbuild install (you must copy the schema to ~/gnome-shell/install/share/glib-2.0/schemas) but it didn't work for me, at least not with the latest GNOME Shell from GIT so if you find a way to get this to work with Gnome Shell compiled with jhbuild, let us know how you've done it in the comments!
Update: the extension is now available in the WebUpd8 GNOME 3 PPA for Ubuntu 11.10.
Update: the extension is now available in the WebUpd8 GNOME 3 PPA for Ubuntu 11.10.
Thanks to Florian for the tip!