Migrating an PPC-partitionmap to a DOS-Partitionmap

Migrating an PPC-partitionmap to a DOS-Partitionmap

Post by Rod Smi » Thu, 26 Jun 2003 23:23:56


> I have got a harddisc with an Apple/ppc partitionmap which I want to change
> into a PC-partitionmap. The main partition on that disc is an XFS. I was
> already able to use it with a linux kernel that supports PPC partitions, but
> I want to change that anyway. Will it be possible? How do I recalculate it
> best?

I doubt if it's practical to convert from one to the other while
preserving the data in the partitions. As I understand it, the PPC
partitioning scheme doesn't require partitions to begin or end on sector
boundaries, which is how x86 partitions are normally created. Thus, it's
likely that you'd need to shift the existing partition around a bit to
make it fit in an x86 partitioning scheme. In theory, you could calculate
the starting and ending points for partitions that would be similar in
size to (but a bit larger than) what you've got now, use dd to shift the
data appropriately, install an x86 partition table, create the x86
partitions, and then use XFS's tools to resize the partition (increasing
its size slightly to fit the new partition). I don't know of any tools
that would do this in an automated way, though, and the number of
potential points of error is such that I wouldn't trust myself to get it
all right when doing it manually. It'd be far safer to convert the disk
by backing up the contents, repartitioning, and restoring the data. (If
that's too tedious, take it as a sign that you need -- and I mean *NEED*
-- better backup hardware.) Alternatively, just don't try to convert;
keep using it with the PPC partition table. Unless that's giving you
problems in a multiboot environment or you need to make this a boot disk,
I don't see any reason not to continue using it that way.


Author of books on Linux, FreeBSD, and networking


Migrating an PPC-partitionmap to a DOS-Partitionmap

Post by I R A Darth Agg » Fri, 27 Jun 2003 06:38:50

On Wed, 25 Jun 2003 16:46:14 +0200,

+> situation. Well, there are some x86-Linux-Bootfloppies/CDs out which can
+> do XFS, but I need to check if they also support PPC partitions. Great
+> would be additional USB2.0 and Firewire support.

You might find these links to be of interest:


Both can be used as live CD's.

Consulting Minister for Consultants, DNRC
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