diff --git a/pages/tools.raid.md b/pages/tools.raid.md
index aa2fba9..7fd6e99 100644
--- a/pages/tools.raid.md
+++ b/pages/tools.raid.md
@@ -21,4 +21,7 @@
 > - https://www.softraid.com/raid/raid_levels/
 
 -----
-snapraid vs. zfs
\ No newline at end of file
+snapraid vs. zfs
+
+---
+https://itsfoss.com/what-is-zfs/
\ No newline at end of file