Corrupted partition table

Garance A Drosihn drosih at rpi.edu
Fri Sep 24 18:45:06 PDT 2004


At 10:07 PM -0700 9/2/04, Matthew Dillon wrote:
:>     Generally when installing DragonFly on a partition that is not
:>     at the beginning of the disk, packet mode is required.  Packet mode
:
:This is not directly related to what happened. The point is that I
:installed DFly on /dev/ad0s2 while Windows was at /dev/ad0s1. The
:first time I reviewed the partition table (after a reboot), I found
:the following:   [...skipped...]
:
    Well, something reinitialized the dos slice table, but I have no
    idea what would have done that.  While the installer does rewrite
    the sector containing the slice table, it does not actually change
    the contents of the table unless you tell it to 'use the whole disk',
    and in that case I think it uses slice 1 rather then 4.  It might
    have been something you played with while you were trying to add the
    DragonFly slice in the first place, that is all I can think of.
So, has this issue with the partition table been fixed yet?  I
just did an install on a new PC, and it left my disk in a pretty
odd state.
I did the following:
  a. install freebsd 5.3-beta5 on the disk.  In this install, I
     created four DOS slices, marked the first two as OpenBSD,
     the third as FreeBSD, and the last one as linux.  I installed
     freebsd into the third slice.  Booted up that install, and it
     was working fine.
  b. while in freebsd, ran fdisk to change the first slice back
     to the standard sysid for FreeBSD/Dragonfly.
  c. rebooted into the install disk for Dragonfly, using the ISO
     from Sept 13th.  This seemed to be the most recent one.
  d. installed dragonfly, told it to use the first slice, and I
     skipped the step where it asked about adding the boot blocks.
     The install itself seemed to go fairly well.  Rebooted.
  e. When I rebooted, I did not get the "boot0" loader (the one
     where it gives you a list of OS's and disks, and you can
     hit an F-key to select the one you want).  It just booted
     right into FreeBSD's "boot1" loader!
  f. I dropped into FreeBSD's boot loader, unloaded the freebsd
     kernel, changed currdev to disk1s1a, loaded /kernel, and
     booted up into dragonfly.  A bit quirky, but it worked,
     and things looked fine.
  g. So, I thought I'd go back to FreeBSD.  I rebooted, again it
     went immediately into FreeBSD's boot1, and this time I just
     let it go.  Now freebsd crashes.  The loader seems to have
     loaded the kernel OK, but it crashed almost immediately after
     starting the kernel.
  h. So, I put the freebsd install CD back in, and figure I'll
     redo that install.  When I go into the fdisk-related step
     in freebsd's sysinstall, it shows me:
        0 through 43006005   -    unused   (!)
          ...              ad4s2  OpenBSD
          ...              ad4s3  FreeBSD
          ...              ad4s4  ext2fs
So, it basically erased the first slice, when it should not have had
any reason to write to any entries in the DOS-level partition table.
This is a new disk with nothing important on it, so if there is some
newer version then I'd be willing to try that.  I'm not really up
for a lot of debugging-effort on my part though.  This is the third
time I've tried to install Dragonfly (over three months), and the
third time it has toasted partitions already in use by other OS's.
--
Garance Alistair Drosehn            =   gad at xxxxxxxxxxxxxxxxxxxx
Senior Systems Programmer           or  gad at xxxxxxxxxxx
Rensselaer Polytechnic Institute    or  drosih at xxxxxxx




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