Re: Grub PARTUUID vs UUID

[Chris Murphy]

On Oct 23, 2013, at 7:58 PM, Chris Murphy <address@hidden> wrote:

> 
> On Oct 23, 2013, at 6:37 PM, FireIcer <address@hidden> wrote:
> 
>> I am looking at the impact in general with changing the grub-mkconfig
>> scan not to pickup and update the grub.cfg with the UUID code but the
>> PARTUUID code instead.
> 
> grub doesn't require volume UUID, this is something that the kernel wants 
> because that's the only reliably present UUID of some kind since MBRs don't 
> have UUIDs. So yes, it's probably marginally more reliable to use the GPT 
> UniquePartitionGUID: a.) there are two copies, checksummed; b.) they're 
> unlikely to change until repartitioning occurs, whereas file system UUID 
> changes if the file system is recreated on an existing partition.

FWIW, the volume UUID is probably more reliable than partition UUID. Here's an 
example. I just resized a file system, and after that, I have to change the 
partition size also. But the tools don't seem to allow changing only the end 
sector value, I have to delete the partition entry then create a new one. When 
I create the new partition entry, I've created a new partition UUID. So if I 
were depending on partition UUID to be stable, and used that instead of volume 
ID, I'd likely have an unbootable system.


Chris Murphy