On 2015-08-25 12:39, Chris Murphy wrote: > On Tue, Aug 25, 2015 at 9:22 AM, Vincent Olivier wrote: > >> For my own sake and other's I would like to maintain (if nobody is already working on that nor needs any help) a centralized human-readable digest of known issues that would be featured prominently on top of the Btrfs wiki. I would merge the Gotchas page and the various known issues pages (including the various multi-device mount gotchas here and there). > > Some way to organize problems by distribution would be needed to be complete. > > For example I don't have the discover & mount by label or uuid problem > you mention on Fedora, since forever. I haven't experienced it on > Fedora 19/20 which is approximately what CentOS 7 is based on. To > figure that out means using one or more boot parameters: > systemd.log_level=debug or rd.udev.debug or rd.debug to find out > what's happening. That would be because the Fedora initrd does a device scan before trying to mount root. Most of the big distro's do this now, but of course you need to be using an initrd for it to work. > The one problem case I still have with the latest versions is multiple > device Btrfs volume UUID doesn't exist when 1 or more devices are > missing. I've seen this myself, but only sometimes. Based on my own testing, it only seems to happen when one of the disks with a system chunk on it is missing (for example, in a 3 device raid1 setup, one of the disks won't have a system chunk on it, and if disk goes missing, I can still mount by UUID fine).