Hello As we know, two file systems with the same UUID (like reported by eg. "blkid") are problematic, especially if both are mounted at the same time it leads to data corruption. So, copying a BTRFS partition with eg. dd to another and use it immediately is bad. To prevent this, "btrfstune -u /dev/sdaX" changes the UUID of the given partition. However, BTRFS subvolumes have their own UUID, which can be viewed eg. with "btrfs sub list -u /mountpoint". This UUIDs are not changed by the command above, and apparently there is no other way to do this. My question is: Is this a problem similar to the main UUID? Can mounting two BTRFS partitions with equal subvolume UUIDs (but different main UUID) can cause data corruption? (...well, and maybe someone could explain me what these subvol UUIDs are for in the first place. Subvolumes already have an unique number, and from user p.o.v, there isn't anything where the subvol UUIDs can be used at all (?)) Thank you PS: Apologies for sending a second mail, somehow my first try didn't contain any text -- 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
