11-2.4 - OpenBSD 2.4 Specific Information

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Table of Contents

• 11.1 - Why do I get UserDir error when running httpd?
• 11.2 - Installing at a partition 4GB or higher
• 11.3 - OpenBSD 2.4 installation walkthrough

11.1 - In 2.4 why do I get UserDir error when running httpd?

It seems as though userdir support was left out of 2.4. Make sure to pick up the patch at:

http://www.openbsd.org/errata24.html

11.2 - Installing at a partition 4GB or higher

The 2.4 cd's shipped with a problem in installboot. A patch can be obtained here http://www.openbsd.org/errata.html. This is fixed in -current.

To place the partition boot record, installboot used a 32 bit multiplication for the sectors times the sectorsize which is larger than 2^32 -1 (i.e. multiplication overflow) when the partition starts at 4 GB or higher. This means the pbr is installed in the real partition address modulo 4GB. It's still possible to install at >= 4GB with some effort:

You have 2 Options for doing so with OpenBSD 2.4. If you have Linux or any other unix like OS, you should back up the sectors first before trying anything.

• Suppose the partition starts at cylinder 611, and the drive has 255 heads, 63 sectors: offset for the obsd partition is 611*255*63= 9815715 sectors. multiply this by 512 and you get: 5025646080. 5025646080 mod 2^32 = 730678784

  (You can just subtract 2^32 on a hand calculator...) dividing by 512 gives sector 1427107.

  Ok, suppose were now in linux (where cylinder numbers are 1 higher btw..) and that the obsd partition is DOS partition 4:

  dd if=/dev/hda of=backup.txt skip=1427107 bs=512 count=1

  will backup the data that installboot will nuke ..

  Now install OpenBSD. Return to Linux.

  Now we're going to copy the partition boot record to the right place.

  dd if=/dev/hda of=pbr.txt skip=1427107 bs=512 count=1
  dd if=/pbr.txt of=/dev/hda4 bs=512 count=1

  (adding obsd to lilo should now work)

  Now write back the nuked sector:

  dd if=/backup.txt of=/dev/hda seek=1427107 bs=512 count=1

  Caveat: make sure that whatever gets nuked by installboot isn't essential to running dd (and starting the other OS). Backing up the affected partition is recommended.

• Use a correct version of installboot (compiled for you by another OBSD'er ..):

  put it on another partition, e.g. a DOS partition. Suppose wd0j is the DOS partition (see disklabel wd0, this is in case of IDE disks), and installboot is named installb there.

  After booting from floppy/CD, press ^C to get into the shell:

  • mkdir dos
    
  • mount /dev/wd0j dos
    
  • cp dos/tmp/installb /usr/mdec/installboot
    

Now enter 'install' and the installation procedure should use the new installboot.