Re: Add device while rebalancing

["Holger Hoffstätte" <holger.hoffstaette@googlemail.com>]

On 04/27/16 17:58, Juan Alberto Cirez wrote:
> Correct me if I'm wrong but the sum total of the above seems to
> suggest (at first glance) that BRTFS add several layers of complexity,
> but for little real benefit (at least in the case use of btrfs at the
> brick layer with a distributed filesystem on top)...

This may come as a surprise, but the same can be said for every other
(common) filesystem (+ device management stack) that can be used
standalone.

Jeff Darcy (of GlusterFS) just wrote a really nice blog post why
current filesystems and their historically grown requirements (mostly
as they relate to the POSIX interface standard) are in many ways
just not a good fit for scale-out/redundant storage:
http://pl.atyp.us/2016-05-updating-posix.html

Quite a few of the capabilities & features which are useful or
necessary in standalone operation (regardless of single- or multi-
device setup) are *actively unhelpful* in a distributed context, which
is why e.g. Ceph will soon do away with the on-disk filesystem for
data, and manage metadata exclusively by itself.

cheers,
Holger