OpenBSD 5.7 Diskless Install Methods

[spauldo]

(NOTE: I'm not talking about using network booting to install onto a disk here. I'm talking about installing OpenBSD to run on a diskless client.)

It seems that OpenBSD 5.7 has changed the layout of the install sets, merging etc.tgz into base.tgz and eliminating a lot of files from /etc.

This makes things a bit harder to set up diskless machines.

Now, I've got two OpenBSD 5.7 machines. One is pretty standard. The other, my firewall, has no disk at all and boots off the first.

In the past, this was pretty straightforward; set up the PXE boot, tftp, etc., untar the install sets you want into a directory exported by NFS, and then tweak some files in /etc. Instant server, please don't add water. Now, however, most of those files in /etc are missing (some are in /etc/examples) and are apparently set up with the install script, seeing as how I have a ton of files on the regular install that aren't in the install sets.

My solution: copy over missing files from the regular install, tweak accordingly, and boot. This works. However, it requires you to have a regular install around, and I'm not entirely sure I accomplished it with no errors that will come back to bite me later.

Since I'm going to have to do this all again someday, I'm interested in hearing proposals for a better way of accomplishing this. Ideally, there would be a bsd.rd that can do a network boot and install onto the NFS server; or, barring that, the install sets laid out in a fashion so that you can boot a system after untarring the sets and get into an install script that will complete the setup process. That's not the world we live in though.

Has anyone here tried this, and how did you accomplish it? Am I missing anything obvious? Any better ideas?

[TronDD]

The etc tarball still exists, it's part of baseXX.tgz Can you just extract it yourself as the installer would? That should get you back to the same starting place as before. Also something like a site tarball might help you manage configurations.

Tim.

[spauldo]

Originally Posted by TronDD

The etc tarball still exists, it's part of baseXX.tgz Can you just extract it yourself as the installer would? That should get you back to the same starting place as before. Also something like a site tarball might help you manage configurations.

Tim.

With 5.6, when you untarred base and etc, you had a working system. It needed tweaking to boot (namely, a hostname.interface and the NFS server in the fstab), but that was it.

With 5.7 that's not the case. A lot of the files are missing. I haven't actually tried booting it, but a lot of the missing stuff was pretty important. The installer does a lot more than just untar an archive in 5.7.

Now, if I was better at shell scripting, I would just adapt the installer script to run on the server in the exported directory on the NFS server before first boot, That would work OK for me, but I'm not sure how portable that would be for people using other Unixes for their NFS servers (sh is sh, but other utilities are subtly different).

The site tarball idea works fine for mass deployments, but you still have to develop it in the first place. What I'm concerned with here is initial installs to a new version of OpenBSD, or people who don't have any regular OpenBSD installs to compare to.

[jggimi]

You have several ways to obtain a "complete" system. Two that come to mind:

• After untarring filesets as before, add two more steps: untar /var/sysmerge/etc.tgz and /var/sysmerge/xetc.tgz
• Run the install script with a spare drive, then dump(8)/restore(8) the resulting filesystem(s) where you want them

[spauldo]

Regarding dump: I've never used it (I came from Linux, and Linus depreciated dump support back in the 2.0.x era, IIRC) - how portable is that? Every try to restore an OpenBSD dump on say, FreeBSD? I might give that a try to see if it works.

Regarding the sysmerge tarballs:

FYI, it looks like those have been moved to /usr/share/sysmerge.

I wasn't aware of those. That's exactly what I'm looking for. And hey, there's a bunch of stuff that goes in /var I never noticed. I touched the log files and that was it.

Thanks, man - that will help a lot next time I have to do this. I'll see about writing up a page about this kind of install when 5.8 comes around.

[jggimi]

FYI, it looks like those have been moved to /usr/share/sysmerge.

They're in /var/sysmerge on -current, which is the flavor I was on when I went looking for them today.

The dump/restore programs are BSD-specific, and not designed for cross-OS file transfers. if your hosting system is a different OS I recommend using some other file archiver, such as tar or perhaps GNU tar.

I use dump/restore because my hosting systems are always OpenBSD, and dump/restore handle long file/path names, links and special files without problems. The only thing they won't transfer are socket files, which is not an issue.

[J65nko]

4.14 - Customizing the install process of the OpenBSD FAQ explains how to add files and how to run a script to tailor the installed system to your personal requirements. Works very well