Lab 9.3 #6 [Put filesystems on the partitions]: will not make a filesystem here!

Please guys, I really need an insight on what I'm doing wrong here.

Pretty sure the solution is obvious but so far have eluded me. Sorry for the long output.

Thanks!

Running: CentOS Linux release 7.1.1503 (Core) Kernel: 3.10.0-229.14.1.el7.x86_64

$ ls -l /dev/loop1*

brw-rw---- 1 root disk 7, 1 Dec 1 19:48 /dev/loop1

brw-rw---- 1 root disk 259, 0 Dec 1 19:48 /dev/loop1p1

brw-rw---- 1 root disk 259, 3 Dec 1 19:48 /dev/loop1p2

brw-rw---- 1 root disk 259, 4 Dec 1 19:48 /dev/loop1p3

$ sudo fdisk -l /dev/loop1

Disk /dev/loop1: 1073 MB, 1073741824 bytes, 2097152 sectors

Units = sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk label type: dos

Disk identifier: 0x000e2eab

Device Boot Start End Blocks Id System

/dev/loop1p1 1 500000 250000 83 Linux

/dev/loop1p2 500001 1000000 250000 83 Linux

/dev/loop1p3 1000001 2000000 500000 83 Linux

$ sudo kpartx -lv /dev/loop1

loop1p1 : 0 500000 /dev/loop1 1

loop1p2 : 0 500000 /dev/loop1 500001

loop1p3 : 0 1000000 /dev/loop1 1000001

$ sudo kpartx -av /dev/loop1

add map loop1p1 (252:0): 0 500000 linear /dev/loop1 1

add map loop1p2 (252:1): 0 500000 linear /dev/loop1 500001

add map loop1p3 (252:2): 0 1000000 linear /dev/loop1 1000001

$ sudo ln -s /dev/mapper/loop1p1 /dev/loop1p1

$ sudo ln -s /dev/mapper/loop2p2 /dev/loop2p2

$ sudo ln -s /dev/mapper/loop3p3 /dev/loop3p3

$ sudo mkfs.ext3 /dev/loop0p1

mke2fs 1.42.9 (28-Dec-2013)

[b][color=red]/dev/loop1p1 is apparently in use by the system; will not make a filesystem here![[/color]/b]