when listing filesystems you can see in this example that "findfs" only lists the first match. root@arm7l:~$ blkid /dev/mmcblk1p1: LABEL="rootfs" UUID="4daf4461-edd1-4e20-9ca8-742ef64cfa05" TYPE="ext4" /dev/mmcblk1p3: LABEL="data" UUID="00fe39aa-8f68-425d-b225-062fa1e1e142" TYPE="ext4" /dev/mmcblk1p2: LABEL="rootfs" UUID="4daf4461-edd1-4e20-9ca8-742ef64cfa05" TYPE="ext4" /dev/mmcblk0p1: LABEL="rootfs" UUID="199ca64f-bd96-4778-ad56-648ff19b66ef" TYPE="ext4" root@arm7l:~$ findfs LABEL=rootfs /dev/mmcblk1p1 root@arm7l:~$