2009-10-27

Installing OpenBSD 4.6, Virtual machine snapshots

OpenBSD's install process changed for the first time in a very long time with the release of 4.6.

For the most part, I feel like the changes are for the better. The install script asks fewer questions, and one can almost accept all the default options without worrying about much of anything. I've already installed it on a few of my systems, but in preparation for my upcoming article on getting OpenBSD, Apache, MySQL and PHP playing together nicely in a chroot environment, I decided to install it in VirtualBox.

Here you can see a new feature towards the top of the screen shot. OpenBSD now asks if you wish to create an initial non-root user. This user will be automatically placed in the wheel group, which has certain administrative abilities in OpenBSD.

At the bottom of this screen shot you can see the partitioning setup. This is similar to the old manual disk partitioning from pre-4.6 installs. It's worth reading up on the OpenBSD installation FAQ, which has a detailed section on setting up disks. Notice that I'm doing a fresh install over OpenBSD 4.5, so the partition table is laid out in OpenBSD's "Whole Disk" mode already. Your partition table may look different.


After that, you get the disklabel, which now has an "auto" option by default for setting up the slices, similar to FreeBSD. I just pressed enter and watched as the filesystems were created.


The installation set selection changed aesthetically, but it's the same as before, there's just not one item per line anymore.


When I test things out, I like the ability to use snapshots in a virtual machine environment. This isn't a unique feature to VirtualBox. I know VMWare can do it as well. I shut down the VM and made a pristine snapshot right after installation, then I started the VM, logged in, got some things configured the way I want (sudo, bash, and PKG_PATH) and made another snapshot after shutting down one more time.


In preparing another OAMP article, snapshots are nice because as I try to get OAMP working, I usually run into snags. Snapshots enable the VM to go back to a previous state and start over from a specific point in time without doing a fresh installation.

Once I think I have the installation procedure down solid, I can revert to the base install one more time and make sure my instructions work. Obviously, virtual machine snapshots have many great uses for both desktop and server instances alike. This is a look into one way I utilize them. For servers, this is a life-saver for backing out of a change gone bad, but it's no substitute for testing changes properly before deploying them to production. Think of snapshots as bookmarks to a virtual machine's past:



One of our readers has already tried the instructions for OpenBSD 4.5 on his new OpenBSD 4.6 installation with some problems. I'll see if I can reproduce the issue and come up with instructions to work through them. Look for an OAMP Chroot article for OpenBSD 4.6 coming soon!

blog comments powered by Disqus