Hi Alex, On 26.03.2012 17:46, Alexander Block wrote: > I used btrfs some time to do incremental backups of large (200GB) VM > images, which worked fine using snapshots and rsync (with --inplace to > preserve COW). > The only problem with this solution is that it takes extremely long > due to rsync's performance on large files. For this reason, I can't > await the btrfs send/receive feature. > The latest discussion regarding send/receive that I know about is this one: > > http://thread.gmane.org/gmane.comp.file-systems.btrfs/12318/focus=12340 > > So my question is, especially to Jan Schmidt, are there any news on > this feature? Well. I'm currently on a side track. To do efficient send/receive, we need working backref resolving. For this, we could define you'll need read-only snapshots before you can send them. Backref resolving on read-only tree structures is working fine[*]. We've got more candidates for backref resolving, though, one of which is the qgroups patch set. This depends on backrefs in live trees, while they're being changed. Thus, although we've got working backref resolving[*] I still haven't dropped that task. I want to get them working on live trees, where my feeling is that I'm getting really close now, but it'll definitely not hit this merge window. (Not to mention that I've been at false "really close"-feelings before.) I want to see the send/receive tool working as soon as possible. Some of the required work for the user space part is already done in my private repository. I could provide that to you, together with a description of what I've got in mind for that tool. We could agree on an interface and then split the task such that you could be doing the user space tool while I'm fiddling with the kernel if you like. -Jan [*] Slightly broken for the scrub-repair case since 3.3-rc1, there's a patch to come for 3.4-rc1 the next days. -- 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
