Stephen John Smoogen wrote:
On Tue, 9 Oct 2018 at 21:47, Yves Bellefeuille yan@storm.ca wrote:
I had CentOS 6 installed on an MBR hard disk. I converted the disk to GPT (with UEFI) and installed CentOS 7 on a new partition.
Um, say *what*?! This wasn't a complete rebuild? Next you'll tell us you buy hardware from Acme, the company that Wile E. Coyote buys hardware.
Was CentOS6 bootable after you converted the disk to GPT? My luck with getting it to work has not been good as the conversion usually changes something very important to the underlying OS which needs a reinstall or a bunch of 'fiddling' in rescue mode before I could get it to work at all.
The EL6 kernel and initrd probably do not have the tools in them to deal with a GPT partition. Your 'best' bet is to boot into an EL6 rescue
<snip> I think they can. However, several things: what I've had to do on our new rebranded Supermicro boxen is to go into the BIOS, and tell it *not* to dual boot (that is, legacy BIOS or UEFI), and *not* legacy, but *only* UEFI.
I will note that we've been using GPT on secondary drives since we started buying drives > 2TB, and that's been a number of years now....
mark