Here you can see two devices are mounted as root:
$ df
Filesystem 1K-blocks Used Available Use% Mounted on
rootfs 29221788 18995764 8761244 69% /
udev 10240 0 10240 0% /dev
tmpfs 203260 2192 201068 2% /run
/dev/disk/by-uuid/1d8879f2-9c47-4a72-9ef4-a6ecdd7a8735 29221788 18995764 8761244 69% /
tmpfs 5120 0 5120 0% /run/lock
tmpfs 406516 376 406140 1% /tmp
tmpfs 406516 72 406444 1% /run/shm
/dev/sda2 29225884 15019636 12741264 55% /home
/dev/sda3 226881528 191247596 24275680 89% /opt
...
However, I didn't specify UUID in /etc/fstab:
proc /proc proc defaults 0 0
LABEL=debian / ext4 errors=remount-ro 0 1
LABEL=istore /mnt/istore ext4 defaults 0 0
LABEL=home /home ext4 defaults 0 2
...
I'd like to see mount info in "/dev/xxx" rather then "/dev/disk/by-uuid/...". Though mount by UUIDs have many advantages, but I prefer to the old style... It's also weired why there are two rootfs mount?