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?
Best Answer
This is a side effect of how the debian initramfs operates. Initially the kernel creates a tmpfs for the root, and unpacks the initramfs, which is a compressed cpio archive, there. The programs and scripts in the initramfs mount the real root device and then
chroot
there. Simply ignore the first entry that lists the filesystem as rootfs, as that is just the initramfs. It is the other one that is your real root filesystem.Since /etc/fstab is in your root fs, it can not be consulted to mount your root fs, so this is done via kernel command line arguments passed by the boot loader. If you are using grub, it uses the UUID by default to avoid problems if the drives happen to be enumerated in a different order. You can edit
/etc/default/grub
to change this behavior, but it is not a good idea.