Am 20.09.18 um 21:52 schrieb David F: > I can't imagine that this isn't a frequently asked question, but with my > poor search skills, I've come up completely empty on this. > > I'm trying to understand why the newer "sophisticated" filesystems (e.g. > btrfs) are implementing raid redundancy as part of the filesystem rather > than the traditional approach of a separate virtual-block-device layer > such as md, with a filesystem on top of it as a distinct layer. In > addition to replication of effort/code [again and again for each new > filesystem implementation that comes along], it seems to be mixing too > much functionality into one monolithic layer, increasing complexity and > the subsequent inevitable increased number of bugs and difficulty of > debugging. > > Of course, the people working on these filesystems aren't idiots, so I > assume that there _are_ reasons simple: after a drive failure * rebuild a 4x6 TB mdraid with 10 GB used * rebuild a 4x6 TB zfs/btrfs with 10 GB used case 1 takes ages case 2 is done within seconds (if only BTRFS would get somehow reliable or ZFS have a proper license)
