HEADS up on HEAD

[Matthew Dillon]

:I'm a long-time follower of HEAD, but I admit I don't understand the
:implications of your warning.
:
:If I build world+kernel now, what kind of tasks should I expect to have
:trouble with?
:
:To be specific, I'm running DF from an extended partition (a bit out
:of the ordinary) /dev/ad1s9a.  Should I expect problems if I update
:just now?
:
:Thanks!

    Well.  I've done my best to test things so hopefully nobody will get
    blown up.  I did test a simple extended partition so it should be ok.

    But, it might be a good idea to do a backup first, just in case.  I am
    messing with the low level disk partitioning code after all!

    Here's what I would do.

    * cp /kernel /kernel.bak

    * buildkernel blah blah, installkernel blah blah, reboot

    It should be able to reboot, the mount device minors don't change,
    only the master raw device and the slice devices, so the new kernel
    should be able to mount everything up even though the devices in /dev
    haven't been upgraded yet.

    If it reboots and mounts the hard disks ok, try the rest of the update.

    * buildworld, installworld, make upgrade

    * I don't think make upgrade will go that deep into the disk devices,
      so after you make upgrade you will have to finish adding the devices
      manually.  Here's a cute trick:

    cd /dev
    ./MAKEDEV ad*s*a

    I still have a bunch more to do.  Only one major piece left that can
    potentially blow things up, but after that the disklabel will be 
    disconnected enough from the disk management code that I can abstract
    it out into a pluggable API and start working on GPT.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>