How to auto-mount /dev/sdb1 to /mnt/s

Hi,
I have installed rancheros 1.1.0, rancher server and agent on bare-metal server in LAN and add cattle environment with some stacks and HA, works pretty fine, except the fact i`m running out free space on /dev/sda1.

So, i followed this page Additional Mounts in RancherOS to use /dev/sdb1 and mount sdb1 on /mnt/s. (using default rancheros console)

Till now i have mounted /dev/sdb1 on /mnt/s but host in rancher server web UI still shows just sda1(64GB).

Untitled

How to acheive that host shows 128GB(/dev/sda1 + /dev/sdb1
Thanks