2011/12/30 Jaromir Zdrazil <jaromir.zdrazil@xxxxxxxx>: >> > Just to add, I would like to see a two way mirror solution, but if it will not >> work now/is not implemnted yet, I would propably choose between drbd in >> asynchronous mode or make a some kind if "incremental" snapshot to a remote >> mapped disk (I do not know yet, if brtfs support it) - it means have one >> shapshop and let's say have a daily incremental update of this snapshot. >> >> You mean like "zfs send -i"? If yes, why not just use zfs? There's >> zfsonlinux project, with easy-to-install ppa for ubuntu. Or you could >> compile it manually. >> > Thank you for your suggestion. As I know, there is not everything ported yet, and one of the missing important features I plan to use is to crypt fs. correct. But btrfs doesn't do encryption as well. And if you're thinking of using luks/dm-crupt to provide encryption for btrfs, there's nothing preventing you to use the same thing with zfs. > And if I am not mistaken, current version does not yet support a mountable filesystem. You're mistaken :) With some extra work, you can even use it as root: - http://zfsonlinux.org/example-zpl.html - https://github.com/dajhorn/pkg-zfs/wiki/HOWTO-install-Ubuntu-to-a-Native-ZFS-Root-Filesystem >> > >> > How would you do it? >> >> If you DO mean zfs-send-like-functionality, then you should ask about >> "btrfs send and receive", not "two way mirror" (which is not an >> accurate way to describe what you want). Also, send/receive ability >> does not mean it can act as two-way mirror. It CAN be an alternative >> to drbd async though. > > If I understand it correctly, the diff between send and receive and two way mirror is that one is synchronous and the other is not (sends the signal that the file have been succesfully written after all/one instance have been succesfully written). > Maybe you can explain it a bit more. Two way: A replicates changes to B, and B can replicate it's own changes to A One way: A replicates changes to B, but B can not replicate it's own changes to A While drbd only supports synchronous mode for active-active setup, the generic "two way replication" does not have to be so. Also, just because something is synchronous does not automatically mean it supports two-way replication. Either way, neither zfs or the (planned) btrfs send/receive supports two-way/active-active setup. Both should (or will) work just fine for one-way replication. -- Fajar -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
