Re: REVIEW: Change mkfs.xfs to set primary superblock inodes in ALL secondaries

[Eric Sandeen <sandeen@xxxxxxxxxxx>]

Barry Naujok wrote:
> One peculiarity of mkfs.xfs that no-one has yet been able to explain
> to me is that all the secondary superblocks do not contain the
> primary superblock's root inode, realtime inodes and quota inodes.
> 
> The root inode is stored in the middle and last AG as well to
> make things more unexpected.
> 
> The following makes all the secondaries the same as the primary
> (other than the global counters).

Also looks good to me.

I've always wondered, too, if writing a single backup superblock in the
last sector(s) of the device at mkfs/growfs time might be sane?

When the primary is corrupt you could quickly get the size of the
device, seek to the end, read on the last 1k boundary, see if it's a
superblock, and use that as the first easily-findable backup.

Just a thought :)

-Eric