Loader, MBR and the boot process
m.seaman at infracaninophile.co.uk
Mon Jan 25 09:45:42 UTC 2010
Andriy Gapon wrote:
> on 25/01/2010 04:41 Robert Noland said the following:
>> On Mon, 2010-01-25 at 07:57 +1100, Mark Andrews wrote:
>>> offset The offset of the start of the partition from the beginning of
>>> the drive in sectors, or * to have bsdlabel calculate the correct
>>> offset to use (the end of the previous partition plus one, ignor-
>>> ing partition `c'. For partition `c', * will be interpreted as
>>> an offset of 0. The first partition should start at offset 16,
>>> because the first 16 sectors are reserved for metadata.
>> Ok, now this has my attention... My gut feeling right now is that this
>> is a bug in geom_part_bsd. I don't understand why the label isn't
>> protected. (Adding -b 16 when adding the swap partition fixes this)
>> Another project to goes on my list...
>> If anyone knows why this is done like this... please share.
> I presume that this is for purely historic reasons.
I believe this has been known about since 5.x days:
As far as I recall, sometime around 6.1-RELEASE this should have been
fixed. It certainly seems to be the case that it is harmless to have
a plain swap partition start at offset 0, but anything else, like encrypted
swap or putting a filesystem there needs the 16 sector offset.
Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard
PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate
Kent, CT11 9PW
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 259 bytes
Desc: OpenPGP digital signature
Url : http://lists.freebsd.org/pipermail/freebsd-questions/attachments/20100125/9641770a/signature.pgp
More information about the freebsd-questions