make-bcache fails with Device or resource busy

[alexbezhan]

Hello. I'm trying to execute: sudo make-bcache -C /dev/sdb
And what I get is: Can't open dev /dev/sdb1: Device or resource busy

Here is more info:

alex@alex-ThinkPad-S5-S531:~$ lsblk -o NAME,MAJ:MIN,RM,SIZE,TYPE,FSTYPE,MOUNTPOINT,UUID
NAME                    MAJ:MIN RM   SIZE TYPE FSTYPE MOUNTPOINT UUID
sda                       8:0    0 931,5G disk                   
├─sda1                    8:1    0     1G part        /boot      
└─sda2                    8:2    0 930,5G part                   
  ├─sysvg-lvswap (dm-0) 252:0    0     4G lvm         [SWAP]     
  ├─sysvg-lvroot (dm-1) 252:1    0    20G lvm         /          
  └─sysvg-lvhome (dm-2) 252:2    0 928,9G lvm         /home      
sdb                       8:16   0  22,4G disk                   
└─sdb1                    8:17   0  22,4G part                   
  └─sysvg-lvhome (dm-2) 252:2    0 928,9G lvm         /home

I want to have a cache on sdb(22.4G)