2011-05-27 10:45:23 +0100, Hugo Mills: [...] > > How could a "subvolume 285" become a "top level"? > > > How does one get a subvolume with a top-level other than "5"? > > This just means that subvolume 287 was created (somewhere) inside > subvolume 285. > > Due to the way that the FS trees and subvolumes work, there's no > global namespace structure in btrfs; that is, there's no single data > structure that represents the entirety of the file/directory hierarchy > in the filesystem. Instead, it's broken up into these sub-namespaces > called subvolumes, and we only record parent/child relationships for > each subvolume separately. The "full path" you get from "btrfs subv > list" is reconstructed from that information in userspace(*). [...]
Thanks, I can understand that. What I don't get is how one creates a subvol with a top-level other than 5. I might be missing the obvious, though. If I do: btrfs sub create A btrfs sub create A/B btrfs sub snap A A/B/C A, A/B, A/B/C have their top-level being 5. How would I get a new snapshot to be a child of A/B for instance? In my case, 285, was not appearing in the btrfs sub list output, 287 was a child of 285 with path "data" while all I did was create a snapshot of 284 (path u6:10022/vm+xfs@u8/xvda1/g8/v3/data in vol 5) in u6:10022/vm+xfs@u8/xvda1/g8/v3/snapshots/2011-03-30 So I did manage to get a volume with a parent other than 5, but I did not ask for it. -- Stephane -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
