* Rich Freeman <ri...@gentoo.org> [150528 08:45]: > On Wed, May 27, 2015 at 8:01 PM, Peter Humphrey <pe...@prh.myzen.co.uk> wrote: [..SNIP..] > UUIDs are often preferable in these kinds of configurations, because > you're less likely to run into duplicate identifiers, they don't > change, and so on. If I mount root=UUID=foo, then my initramfs will > try really hard to find that partition and mount it. If I mount > root=label=foo then it will still try hard, but if for some reason I > have more than one device with that label I could end up booting from > the wrong one. If I mount root=/dev/sda1 then my boot may fail if I > add a new drive, if the kernel behavior changes, if the udev behavior > changes, and so on. > > I don't believe either the kernel or udev makes promises about device > names being stable. It often works out this way, but it isn't ideal > to depend on this. > > -- > Rich
It's worse than just getting the wrong filesystem mounted if the wrong filesystem gets mounted as /tmp. OpenRC's bootmisc will wipe the /tmp directory at boot (and likely systemd as well, but I haven't checked.) This means if disk device names get shifted and something other than the proper /tmp device gets mounted as /tmp then it's "restore-from-backups" time. This happened to me and wiped /home (the /dev/md* devices got renumbered once.) So I've switched to UUID mounts so that problem doesn't happen in the future. It's really unpleasant if that happens. Todd
