Re: Disk Problems

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Mon, 7 Jul 2014 21:36:50 +0200
    From:        Ib-Michael Martinsen <i.m.martinsen%gmail.com@localhost>
    Message-ID:  <21434.63186.93527.47955%asus.immnet.dk@localhost>


  | I noticed the comments on the -b option. The problem was, I
  | could not get fdisk to display it's supposed action anyway
  | other than with the above statement (where it says, what it is
  | going to do, but does not!).

The "but does not" is (I think) partly so it is possible to see what
would happen, without actually doing anything - if you're not careful
(or more likely now, if you weren't careful, in older times) some of
these changes can (could) screw things badly in ways that can (could)
be hard to recover from.  Being able to make dry runs is kind of nice.

  |  > Try
  |  >  fdisk -u -f -b 1024/63/63 /dev/rwd1d
  | 
  | I did that with no success:
  | 
  | root@asus:/root # fdisk -u -f -b 1024/63/63 /dev/rwd1d
  | fdisk: Partition data not specified

Yes, I should have tested that one more .. I wondered if perhaps
one of the other options might be needed with -u -f to actually
change something on one of the partitions....  (ideally just the
-b should be enough, but that doesn't mean the code allows it,
and obviously, it doesn't.)


  | I tried that one too:
  | 
  | root@asus:/root # fdisk -u /dev/rwd1d

  | gives the unexpected result:
  | 
  | root@asus:/root # fdisk /dev/rwd1d
        [....]

  | It seems that fdisk will not do what I command!

That is weird.

  | I don't know if some part of (the beginning of) the disk
  | is write protected?

NetBSD (software) write protects the label, so ordinary processes
cannot overwrite it, but fdisk disables that protection (as it is
deliberately writing there, not accidentally).   Hardware protection
(something inside the drive) is unlikely - and fdisk ought to
complain if any of its writes failed.   I suppose it is possible the
drive is refusing to write those sectors, but not returning any kind
of error, but if that's the case (which seems unlikely to me) I'd have
that drive in the trash, and never buy from that manufacturer again!
I've certainly never seen anything like that.

But what the problem might be for this is beyond my understanding, x86's
and their weirdnesses are somewhat mysterious to me.

  | For peace of mind I still would like the disks to be
  | identically configured, but you have me almost convinced
  | it is not necessary.

Your config as you have it looks fine to me, I wouldn't be worried at all
about the strange c/h/s numbers.   The inability to change them however is
something that might be of concern, if no-one is able to explain that one.

kre