Load and unload files into kernel

You can use kldload command to load files into kernel. For example, enter /boot/kernel directory, and use kldstat to check currently loaded files: 

  1. # cd /boot/kernel
  2. # kldstat
  3. Id Refs Address            Size     Name
  4.  1    6 0xffffffff80200000 17bc6a8  kernel
  5.  2    1 0xffffffff81a11000 56c6     fdescfs.ko
  6.  3    1 0xffffffff81a17000 2ba8     uhid.ko

Use kldload to load zfs.ko file: 

  1. # kldload zfs.ko
  2. # kldstat
  3. Id Refs Address            Size     Name
  4.  1   15 0xffffffff80200000 17bc6a8  kernel
  5.  2    1 0xffffffff81a11000 56c6     fdescfs.ko
  6.  3    1 0xffffffff81a17000 2ba8     uhid.ko
  7.  7    1 0xffffffff81a1a000 1ee0c8   zfs.ko
  8.  8    1 0xffffffff81c09000 3330     opensolaris.ko

You can see the zfs.ko is loaded successfully.

Unloading file uses kldunload command: 

  1. # kldunload zfs.ko
  2. # kldstat
  3. Id Refs Address            Size     Name
  4.  1    6 0xffffffff80200000 17bc6a8  kernel
  5.  2    1 0xffffffff81a11000 56c6     fdescfs.ko
  6.  3    1 0xffffffff81a17000 2ba8     uhid.ko

Reference:
kldload;
kldunload.