I am confused with this: should I call it the "root subvol" or "top-level subvol" or "default subvol" or doesn't it matter? Are all subvols equal, or some are more equal than others [hark to Orwell's Animal Farm ;-)]?
And more importantly, is the ID of the root subvol 0 or 5? The Oracle guide (https://docs.oracle.com/cd/E37670_01/E37355/html/ol_use_case3_btrfs.html) seems to say it's 0 : "By default, the operating system mounts the parent btrfs volume, which has an ID of 0" but the BtrFS wiki (and btrfs subvol manpage) reads 5: "every btrfs filesystem has a default subvolume as its initially top-level subvolume, whose subvolume id is 5(FS_TREE)." as also the Ubuntu Wiki: "The default subvolume to mount is always the top of the btrfs tree (subvolid=5)." Now this Oracle page http://www.oracle.com/technetwork/articles/servers-storage-admin/advanced-btrfs-1734952.html says: "The only clean way to destroy the default subvolume is to rerun the mkfs.btrfs command, which would destroy existing data." So from what I've (confusedly) understood so far, 0 refers to the superstructure (or whatchamacallit) of the entire BtrFS-based contents of the device(s) and hence cannot be deleted but only reset by a mkfs.btrfs, but 5 is only the default subvol (mounted when the FS as a whole is mounted without subvol spec) provided by mkfs.btrfs, and subvol set-default can have another subvol mounted as default instead, after which 5 can actually be deleted? [confused]... -- Shriramana Sharma ஶ்ரீரமணஶர்மா श्रीरमणशर्मा -- 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
