fstab

# <file system>                 <mount pt>      <type>  <options>                                       <dump>  <pass>
/dev/system_a                   /               ext4    ro,noload,noauto,noatime,errors=remount-ro      0       1
/dev/data                       /mnt/root_data  ext4    rw                                              0       0
proc                            /proc           proc    defaults                                        0       0
devpts                          /dev/pts        devpts  defaults,gid=5,mode=620,ptmxmode=0666           0       0
tmpfs                           /var            tmpfs   mode=0777                                       0       0
tmpfs                           /dev/shm        tmpfs   mode=0777                                       0       0
tmpfs                           /tmp            tmpfs   mode=1777                                       0       0
tmpfs                           /run            tmpfs   mode=0755,nosuid,nodev                          0       0
sysfs                           /sys            sysfs   defaults                                        0       0