[dm-devel] geometry of dm devices......

[Darrick J. Wong]

Peter Koutoupis wrote:

>> I understand the HDIO_GETGEO is an unsupported feature to dm 
>> devices....but under normal practices how would a normal end-user be 
>> able to obtain such geometry from a raw dm device?  I have read of 

Wow, I'm late to the game.  If your kernel/software are new enough, you
can set a dm device's geometry via the DM_DEV_SET_GEOMETRY_CMD ioctl.
iirc, the userland equivalent is:

# dmsetup setgeometry /dev/foo cyl head spt start

...after which HDIO_GETGEO should return nonzero values.

You'll need kernel 2.6.16+ and I think the requisite version of dmsetup
is 1.02.  And to my (very limited) knowledge of multipath, geometry is
not set up automatically.

--D

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 191 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/dm-devel/attachments/20060808/d64e4c53/attachment.sig>