On Tue, Feb 19, 2008 at 12:46:28PM +0000, Daniel P. Berrange wrote:
On Tue, Feb 19, 2008 at 03:43:11AM -0500, Daniel Veillard wrote:
+ + /* + * LVM requires that the first 512 bytes are blanked if using + * a whole disk as a PV. So we just blank them out regardless + * rather than trying to figure out if we're a disk or partition + */
is it really 512 or the block size on the device used ? But 512 is probably sufficient for LVM to consider it cleared, just wondering ...
The 'pvcreate' man page explicitly says the first sector
<quote> For whole disk devices only the partition table must be erased, which will effectively destroy all data on that disk. This can be done by zeroing the first sector with:
dd if=/dev/zero of=PhysicalVolume bs=512 count=1 </quote>
So 512 is fine for MSDOS partition tables at least.
Ahh, the legacy :-) thanks for the explanations ! Daniel -- Red Hat Virtualization group http://redhat.com/virtualization/ Daniel Veillard | virtualization library http://libvirt.org/ veillard@redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/ http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/