diff --git a/suckless/virtual.mdwn b/suckless/virtual.mdwn
index fbcc13b5fb505d3900c019cad71686c9828a6360..51c01c14c0f92f198cd57101d82f357fa1c852b5 100644
--- a/suckless/virtual.mdwn
+++ b/suckless/virtual.mdwn
@@ -97,3 +97,5 @@ Image optimization:
 
 * [Tip: Making a disk image sparse | Richard WM Jones](https://rwmj.wordpress.com/2010/10/19/tip-making-a-disk-image-sparse/).
 * [How to convert a non-sparse image to a sparse image – Patrick's Blog(2)](https://blog.laimbock.com/2013/10/31/how-to-convert-a-non-sparse-image-to-sparse/).
+
+    ionice -c 3 nice -n 19 virt-sparsify --tmp /tmp --convert qcow2 --compress box.img box.new && mv box.new box.img