selinux woes, was Re: [SATLUG] swapping 2 HDDs = problems

[Travis H.]

Status report follows.

> >But, when I boot up with the big drive on the secondary controller, it
> >complains about trying to read past the end of the drive.  I think I
> >have LVM enabled, and so maybe something in LVM is referencing the big
> >drive as /dev/hda instead of /dev/hdc as it is now.

That is exactly what happens.  LVM stores the device name in the
logical extents.
If you have an editor capable of editing a device file, you can change
it directly.
I ended up masking the extra partitions by changing their system ID to AIX.

> offhand, I'd say burn an iso of a live cd (which ever distro has one - I
> have Whax, here - works good)
> then mount the drives and do what you need, rebuild lilo/grub, pull the
> cd out, and boot the machine again.

I tried this.  First I tried using "star" to copy the files plus
selinux attributes off the old drive.  I had to play around with
shared libraries and it just coredumped all the time.  Next I copied
the files over using dump/restore, but they lacked selinux contexts
(the bootable distros I tried don't have selinux enabled -- gee I
wonder why).  I am paranoid and wanted to run selinux on this box,
just to gain familiarity with it.  Boy did I ever!  Basically with
selinux enabled, even in permissive (non-enforcing) mode, I couldn't
write to any file.  You see, / had no security contexts, and therefore
I had no permission to do anything under it.  I tried *everything*. 
With selinux disabled, you cannot edit security contexts.  Catch-22. 
So basically I had to boot up off the old drive, mount new / as /mnt,
and "chroot /mnt fixfiles relabel" to relabel everything on the new
drive's /.  Couple this with problems associated with two drives
having the same labels, and it made for many hours of effort with no
discernable results.  I highly recommend it to someone who doesn't
want to accomplish anything and has 6 hours to kill.
-- 
http://www.lightconsulting.com/~travis/
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