On Tue, Nov 10, 2009 at 2:25 AM, Mikael Abrahamsson [off-list ref] wrote:

On Mon, 9 Nov 2009, Doug Ledford wrote:

quoted

Of course, I recently had a bug report that I ended closing out as NOTABUG
because of this very ability.  The person had arrays with 1.2 superblocks,
and they went to add a new disk, and all the existing disks had a specific
partition layout, so he copied that to the new disk, then tried to add the
partition to the raid array.  It kept returning "device too small for
array".  Then, upon inspection, we come to see he has a 1.2 superblock on
the *entire* drive, which left the partition table intact, but the partition
table is *pointless* because the array is on the whole disk devices.  This
sort of confusion is bad.  So, while I could see making it 1.2 for
partitions (so that boot sectors won't overwrite the superblock), I wouldn't
make it 1.2 for whole disk devices, and in fact it might be wise to refuse
to create 1.2 superblocks on whole disk devices.  Just a thought.

Well, same thing there, if you create a partition table you don't break the
superblock. Perhaps something needs to be able to discern between the
superblock being "whole disk" and on a partition? Personally I put 1.2 on
"whole disk" (no partition table at all), and I would really HATE this
possibility going away. I like it the way it is and feel comfortable with it
and I don't want 1.0 or 1.1 superblocks in my setup.

Since I almost always use partitions (this way, the partition *type*
is "Linux RAID") I largely avoid this issue.

-- 
Jon
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html