I posted a few times previously about running Ubuntu in a virtual machine in OS X (here), but I had some difficulty in retracing my steps six months later.
So I thought I would cover the ground again, and expand it. This time I will talk mostly about things that do work, not about my trials and tribulations on the way.
I don't have the luxury of a separate computer to run Linux. So it's very nice that there is a free virtual machine available for me to play with called VirtualBox (wikipedia). Thanks, guys. (It's an Oracle product these days).
I downloaded and installed VirtualBox 4.1.10 for OS X.
For Ubuntu, there is a choice of 32-bit or 64-bit and Desktop or Server. For example:
These designations stand for Intel 80386 32-bit, and AMD x86-64, 64-bit. Either one will work. I chose standard Linux Ubuntu version 11.10 ("Oneiric Ocelot") 32-bit this time. It does not matter that my machine has an Intel chip.
I want to do server-like stuff, but I do find it handy sometimes to have a GUI (e.g. for Firefox and Dropbox), and also I thought it might be instructive to add the relevant software one piece at a time, starting with Apache2. In the Desktop, the 32-bit version is recommended.
The .iso file type is described here. It is basically an archive file format for an optical disc.
After intalling VirtualBox I ran the Oracle VM VirtualBox Manager, which first lead me through setup of a new virtual machine, where I accepted all defaults except that I boosted the RAM to 2048 MB. (I don't plan to do much work on the OS X side while the server is running). Starting the VM gives a "First Start Wizard" which has a dialog where you should navigate to the stored .iso file. I am always too impatient to actually read the instructions, but in this case it would be good to read chapter one of the VirtualBox docs or at least this part of it: Starting VirtualBox.
The install doesn't take long, 10 minutes or so. I had trouble (on several installs) where I had wandered away to the OS X side, and when the install finished and wanted to restart Ubuntu it did bad things to OS X, forcing a hard shutdown with the power switch. So, make yourself a sandwich or something.
At the end, bring up the Terminal. How to achieve this was puzzling at first. A shortcut I found on the web is to do CTL-OPT-t. Another simple method is to search for Terminal after clicking the "dash" icon at the top of the "launcher"---a dock lookalike.
There are methods to add the Terminal to the launcher, but these involve right-clicking, which seems problematic with this setup. I'll have to investigate and get back to this later. I got it to work on my laptop by the two-finger-tap method, but it's not working now on the mini.
Now, the very first thing is to do:
sudo apt-get update
A GUI Update Manager will come up when this finishes, with many items to update (≈ 350). I did this too, though I suspect it's unnecessary for us and it took a long time.
In order to get cut-and-paste to work, we will need what are called the "Guest Additions" from VirtualBox. First, type in this command:
sudo apt-get install dkms build-essential linux-headers-generic
When it's done, restart Ubuntu. Then, from the VirtualBox menu above the Ubuntu window, from Devices choose mount Guest Additions. This "mounts" a "CD" in Ubuntu, when you click on that it will ask you whether you want to run the software, which you should do. When it's done, reboot Ubuntu again, and then "eject" the disk.
Now, cut-and-paste should work between OS X and Ubuntu. The only trick is that you need to click in the Ubuntu/Terminal window twice, once to shift focus to Ubuntu, and then to shift focus to Terminal. For Terminal, we do CTL-SHIFT-v and -c. (If you're in the Text Editor, just do CTL without the SHIFT).
Now, we'll grab two more packages:
sudo apt-get install apache2
sudo apt-get install openssh-server
And at this point, I saved a snapshot of the VM from VirtualBox (under Machine > Take Snapshot). To shut down (in OS X), just click on the red close button (top left of window) and then choose "Save State."