i'm having troubles in a RaspberryPi2 mounting a USB as the / partition.

I modified /boot/config.txt adding (also tried with original cmdline.txt, but I think that's the cleaneast way):


Then, in my-cmdline.txt, I have:

boot=UUID="35bb7f91-9dc2-4c20-a1c3-f99aa7fbe2f5" rootfstype=ext4 rootwait quiet osmcdev=rbp2

When de system boots, /proc/cmdline has:

coherent_pool=1M bcm2708_fb.fbwidth=1920 bcm2708_fb.fbheight=1080 bcm2708_fb.fbswap=1 smsc95xx.macaddr=B8:27:EB:5A:28:01 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000  root=UUID="35bb7f91-9dc2-4c20-a1c3-f99aa7fbe2f5" rootfstype=ext4 rootwait quiet osmcdev=rbp2

I checked the USB stick has exactly the UUID I'm using:

lrwxrwxrwx 1 root root 10 oct 19 16:05 35bb7f91-9dc2-4c20-a1c3-f99aa7fbe2f5 -> ../../sda1

But when I check the mounted devices, I get the following:

/dev/mmcblk0p2 on / type ext4 (rw,noatime,stripe=1024)
/dev/sda1 on /media/35bb7f91-9dc2-4c20-a1c3-f99aa7fbe2f5 type ext4 (rw,nosuid,nodev,relatime,stripe=1024,uhelper=udisks)

What am I missing? Why it's not mounting the device?

Although, if I try to mount the device by PARTUUID instead of UUID it says it's trying to mount an unexisting device...

2 Answers 2


It is not possible to mount a UUID on boot as the Pi firmware does not support this.

Use PARTUUID (which Raspbian does by default).

It is not impossible, but you would need additional initrd with UUID support.


In your my-cmdline.txt file, you specify 'boot'. This should read 'root'. As Milliways answer points out, you cannot (easily) change your /boot partition location as raspian expects it to reside on the SD card.

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