On Wed, Jun 08, 2016 at 09:11:30AM +0200, Christoph Hellwig wrote: > On Fri, Jun 03, 2016 at 08:54:15AM +1000, Dave Chinner wrote: > > On Thu, Jun 02, 2016 at 04:19:07PM +0200, Christoph Hellwig wrote: > > > I've had some vocal user requests to allow enabling reflinks at run time, > > > which happens to be a mostly trivial feature. The only caveat is that we > > > need a large enough log size to support the reflink requirements, but for > > > typical large file systems that's not an issue. > > > > Hmmm - how does this interact with all the rmap code? I was not > > planning on enabling reflink without rmap and vice versa simply > > because it makes the validation and testing matrix vastly more > > complex. > > Uh. So far I've only been testing pure reflink code, mostly because > rmap really doesn't buy much for the use case I'm working on. So far I've mostly been testing with mkfs.xfs -i sparse=1 -m rmapbt=1,reflink=1 on the assumption that sparse will get turned on soon and that it might help a lot in the post-COW fragmentation world. (Hoping that the cowextsize defaults avoid most of the horrifying fragmentation that we see on the second- and last-letter filesystems.) > Enabling rmap post-mkfs is defintively a different ballpark, and probably > not worth it even if it would be doable. Hughflgrgh. I wasn't even going to consider /that/ possibility. :) (I guess you could flip on the feature bit and run xfs_repair...) --D _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
