Omitting partitions

[beavers]

Doing a fresh install on some new hardware, and was racking my braing trying to determine if there's any issue with omitting entirely the separate partitions for /usr/src, /usr/obj, and /usr/X11R6. I won't ever be building from source, nor building ports, nor installing the xenocara set. Is there any other reason to keep these partitions around?

[ibara]

You're free to omit /usr/src and /usr/obj if you know you will never build anything, and omit /usr/X11R6 if you know you will -x* on install. But you should keep /tmp, /var, /usr, and /usr/local around.

[bsd-keith]

On my home systems - I only have / & /home partitions - works well for me.

[jggimi]

Originally Posted by bsd-keith

On my home systems - I only have / & /home partitions - works well for me.

You are lucky, then. This can cause boot failures on i386 and amd64, depending on a) BIOS sector addressing limits, which vary from BIOS to BIOS, and b) the LBA locations of the inode and data containing the /boot second stage bootloader, which moves with every install or upgrade.

[bsd-keith]

That surprises me, as this is how I've always installed it on my computers.

[jggimi]

The FAQ used to have a discussion on this. While it no longer does, old copies exist in the www CVS repository. Take a look at Section 14.8 of this 2012-era version of FAQ Chapter 14.

[jggimi]

And, yes, people are still having boot problems because of this. See this discussion from misc@ that occurred two weeks ago. Or this one from bugs@ from this week.

[bsd-keith]

Wowza! I usually choose whole disk, then create a custom label, using z to clear what might be there, then create the a partition as / then add the d partition for /home.

Guess I've been lucky

[jggimi]

Along with your continued good luck, you also operating with some security risks that would be mitigated by being selective with the mount options used by each partition.

As one example of many, your current configuration prevents you from running binaries with OpenBSD's W^X security protection enabled.

[hitest]

Originally Posted by jggimi

Along with your continued good luck, you also operating with some security risks that would be mitigated by being selective with the mount options used by each partition.

My understanding of the extensive disk layout system of OpenBSD is that it helps to mitigate security risks. I think I may have read that in Absolute OpenBSD. I keep the default partition layout. I may use a custom layout in that I will vary the size of each partition a bit, but, I keep the default partitions.

[LeFrettchen]

Originally Posted by hitest

I may use a custom layout in that I will vary the size of each partition a bit, but, I keep the default partitions.

The same here, I just adjust some sizes...

[jggimi]

Automatic allocation defines 10 partitions for drives greater than 8GB, 4 partitions for drives between 8GB and 2GB, and 2 partitions (swap, root) for drives smaller than 2GB. Admins can also define their own templates, too.

Years ago, I used to recommend two partitions (swap, root), for the purpose of provision sizing prior to production deployment. This was because disk layout needs were sometimes hard to predict in advance. However, the boot limitation issue would sometimes occur, making this a less-than-practical recommendation. At the same time, storage capacities increased dramatically, making pre-launch testing for final layouts much easier for admins to conduct. I stopped recommending it.

[jmccue]

There is no harm, I did that in the past but but after a bit of research I would suggest you put /usr/local in it's own partition.

The reason I suggest that is you can avoid using mount option 'wxallowed' on all drives except on /usr/local