Re: [Ext2-devel] [RFC 0/13] extents and 48bit ext3

Jeff Garzik
2006-06-10T01:09:27Z

Theodore Tso wrote:
> Jeff, you seem to think that the fact that the layout isn't precisely
> the same after an on-line resizing is proof of something horrible, but
> it isn't. The exact location of filesystem metadata has never been
> fixed, not in the past ten years of ext2/3 history, and this is not a
> big deal. It certainly isn't "proof" of on-line resizing being
> something horrible, as you keep trying to claim, without any arguments
> other than, "The layout is different!".

No, I was proving merely that it is _different_. And the values where
you see a _difference_ are the ones of which are no longer sized
optimally, after you grow the fs to a larger size.

So you incur a performance penalty for resizing to size S2, rather than
mke2fs'ing the new blkdev at size S2. Certainly within the confines of
ext3 that cannot be helped, but a different inode allocation strategy
could improve upon that.

Jeff