Good ol’ Secure Shell or SSH — who would want to live without them!? To give you a text-book definition; SSH is a network protocol that allows data to be exchanged using a secure channel between two networked devices. Now that we’ve gotten that out of the way, let get down to business. You’ve got a fresh install of Fedora 15, with that wonky GNOME 3 desktop, and need to figure out how to enable SSH. This article is simply a barebones way of getting started. There’s a better method to make the SSH session more secure, but I haven’t researched that yet.In order to run some of the commands you’ll need to have the root account’s password.

Enable SSH Daemon

First things first, let’s make sure that the ssh daemon is running. Without that we’re not using this service at all. Open gnome-terminal and type:

$ su -
Password:
# systemctl start sshd.service

Now that it’s started you’ll need to keep it going in case you reboot your machine. Run the following command to have it start on-boot:

# systemctl enable sshd.service

After executing that command I received the message below. Tomasz Torcz was kind of enough let me know that the above command will redirect to chkconfig until systemd unit file is shipped with sshd.

sshd.service is not a native service, redirecting to /sbin/chkconfig.
Executing /sbin/chkconfig sshd on

Verify Firewall Setting

By default port 22 is open in the firewall, but it’s good to double check. Open system-config-firewall. You can either type in that name or navigate to Activities | Applications | Firewall.

Test the Connection

The easiest way to test is run the ssh command in your terminal. Another method is installing an SSH client on your Android device (ConnectBot) or installing PuTTY on your Windows machine. If you’re going to test the connection on the same machine, simply open gnome-terminal and type:

$ ssh user@hostname

For instance my username is “marc” and my computer is 10.0.0.2 (I could never figure out how to configure my hostname properly). So; I type in ssh marc@10.0.0.2. I’d get a warning message saying:

The authenticity of host ’10.0.0.2 (10.0.0.2)’ can’t be established.
RSA key fingerprint is [some long identification number in 2-digit sequence]
Are you sure you want to continue connecting (yes/no)?

Once I typed in “yes”, I was then able to type in my password for “marc” and continue on. That’s it. Have fun SSHin’ into your machine from remote places.

I’ve run into this issue from time to time and I would normally have to reboot.  So; one day I said, “No more!  This is LINUX and I should be able to work around it.”  Oh!? What issue am I talking about?  When your GNOME panel gets stuck and there’s nothing you can do about it!  I’m going to show you how to kill your gnome-panel process and then restart it.  Note that it’s only a temporary solution – I know there’s a better way, but this will do for the time being.

When your GNOME panel goes on the frizz you can kill the process using the “pkill” command.  The only issue with this is once you start the gnome-panel it’s not so stable and it’ll reset to factory defaults.  No worries though once you reboot it will resume to your normal configuation.  So; to kill a mocking bird… ah I mean a gnome panel:

pkill gnome-panel

Reanimate the Panel You Just Killed

After the panel goes away, you then want to bring your Frankenstein back to life.  Open a Terminal window and type “gnome-panel”.  That will start your GNOME panel process.  The only trick with this command is where you execute it.  Since it’s being executed in a Terminal window, you’re bound by it.  If you stop the command or close that terminal, your GNOME panel will go away, again.  After you run the command, simply minimize that Terminal window and go about your business.  JUST TO RESTATE, THIS IS ONLY A TEMPORARY SOLUTION.

Make sure you visit the GnomePanel page for more insight on this very useful module.

I’ve ran into this issue, from time to time, where I can’t access my graphical system monitoring tool (System Monitor) to kill processes. Luckily at that time I do have access to Terminal. The next question is, “Well; how do I view the processes running and how do I kill them?” Good question (I sound like a schizophrenic), let me tell you how to view your active processes, all processes, and how to MDK (murder death kill; Demolition Man reference) them.

Bash Command, “PS”

Open your terminal of choice and you will have the bash command “ps” available to you. “PS” stands for “process”; simple enough. You can find more about the bash command by typing in “man ps”. It will bring up the “man page” (Linux User’s Manual).

1. Type “ps -e” or “ps -A”, to list all processes running, and press <ENTER>.
2. Scroll down to find the program you want to kill and remember the process id number (pid).
3. Then type “kill {pid}” and press <ENTER>. Replace {pid} with the actual process id number.

Example:

In this example, we’ll say that tomboy was causing your system to freeze up and you needed to get rid of that process. After you execute the command “ps -e” to see all processes, find “tomboy” and remember the pid in the first column. Then run the kill command.

ps -e
kill 3009

Understanding the “Process”

According to the Linux User Manual, “ps” reports a snapshot of the current processes. What are processes, yeah this might be a good time to explain that. Check out Wikipedia… isn’t that where everyone gets their solid facts from!? Well anyway, a process is a running program; a task to be executed, especially one which is largely self-contained. Seriously; I’m not going to write a lot about it. Wikipedia has a lot more information.

“X” Marks the Spot

This command is very convenient and may be quicker than finding the process then killing it.  If the program that’s causing errors is right there in the open… then open your Terminal and type in “xkill”.  This will change your mouse pointer to a skull and crossbones.  Make sure you can easily see the program.  Once you click on it, Linux will kill the program clicked.  Pretty neat, eh!?

Rant: Here’s my ordeal with this horrible error, at least to a noob in linux, like myself.  I couldn’t figure out why I was getting this error.  When I opened Evolution I would get a pop-up saying “Summary and folder mismatch, even after a sync”.  I thought it was my mail stored on my server, I have 4 pop accounts and I ended up deleting all the old emails 500+ each (Yeah I’m a pack rat).  It was literally driving me crazy because it wanted to redownload ALL my old emails.

Well after all that foolishness I finally figured out the solution.  Most sites I visited stated the same solution to the problem, go into the ~/.evolution/mail/local/ and delete any file that had .ev-summary relating to the pop-up error.  So; if your inbox was giving you the problem then you would delete Inbox.ev-summary.

My problem was even after I deleted that file I was still getting the issue.  After a couple days of pulling my hair out of my head…  Finally I ended up looking at the directory through gnome-terminal and I saw an extra file that’s not visible in a GUI file browser.  It ended witha  tilda (~), Inbox.ev-summary~.

I’ve noticed in linux that any file ending with a tilda is treated like a backup file, it’s also hidden to the naked eye.

Once I removed that file – everything was back to status quo.  What a trip!  I’ve been on forums, mailing lists – you name it.  I haven’t properly checked my mail in Evolution within the past couple days.  I’m glad that’s all over with!  Linux rocks!