Is it possible to install FreeBSD on a single MBR slice with ZFS ?

[Thomas Mueller]

(snip)

> > But following the migration, I have made a serious error. I used
> > Windows (ada0s1) to delete ada0s2 :
> > Windows has rearranged the MBR table to make ada0s3 -> ada0s2.

> Sounds like something OS/2 has done to me many years ago. :-)



> > I am now struggling to fix the MBR table.

> Of course.



> > If you have any tips, that shall be wonderful

> Do not and never use "Windows" to deal with lower level aspects of
> your disk. It will for sure mess things up, and in worst case, you
> need to reinstall everything from scratch. Of course you don't, as
> you have a working backup you can rely on. ;-)

> It's not as easy anymore to fix partition table entries with a simple
> handheld calculator and "Norton Disk Editor" started from a handy DOS
> boot floppy. :-)
        
> For the future: Bootable CDs like UBCD or PartEd Magic provice
> excellent tools to deal with re-partitioning. You can use FreeBSD's
> editor as well, especially if all you want to do is delete some
> MBR slices. It's the first thing you do in the installer, then
> follow to create new slices as you need them, and go on with the
> installation process.

> Polytropon

With either gpart or Rod Smith's gdisk, and I believe also NetBSD's gpt, you can save the GPT partition table data to a file, preferably on a different disk, such as a USB stick, and restore if the GPT partition table is damaged.

Backup partition-table data file would have to be restored from the same partitioning software.

This requires a USB-stick or other off-disk installation of FreeBSD that would include gpart or gdisk; gdisk also can be used under Linux.

This would be better than Norton Disk Editor + handheld calculator + DOS boot floppy.

Your mention of OS/2 reminds me that this month, or about 10 days ago, marks the sixteenth anniversary of the crash with OS/2 Warp 4.  On rebooting, OS/2 CHKDSK ran automatically and ran amok, trashing all data on my second hard drive in addition to partition data on the smaller, first hard drive.

I was never able to boot OS/2 again, even from maintenance or installation floppies, result was Trap 000e or Trap 000c.

I believe OS/2 Warp 4 had better hardware support than FreeBSD or NetBSD back then, 16 years ago, but since then OS/2 and its successor, eComStation, have not kept up, and now FreeBSD and NetBSD seem to be far ahead of eComStation.

Tom