lvcreate / lvextend / lvm / lvs / vgcreate / pvcreate

LVM (Logical Volume Manager).

$ sudo pvcreate /dev/sdb /dev/sdc
$ sudo vgcreate data_vg /dev/sdb /dev/sdc
$ sudo lvcreate -L 100G -n logs data_vg
$ sudo lvextend -L +20G /dev/data_vg/logs
$ lvs