diff --git a/docs/quick.md b/docs/quick.md
index e21f750a..441923d7 100644
--- a/docs/quick.md
+++ b/docs/quick.md
@@ -15,7 +15,7 @@ meets the following prerequisites:
 | Ubuntu/Debian   | open-iscsi            |  <ul><li>sudo apt install open-iscsi -y</li><li>sudo systemctl enable --now iscsid</li></ui>| sudo systemctl status iscsid.service |
 | RancherOS        | open-iscsi            |  <ul><li>sudo ros s enable open-iscsi</li><li>sudo ros s up open-iscsi</li></ui>| ros service list iscsi |
 
-3. You have disks attached to nodes to provision storage.
+3. You have disks attached to nodes to provision the storage. The disks MUST not have any filesystem and the disks MUST not be mounted on the Node. cStor requires raw block devices. You can use the `lsblk -fa` command to check if the disks have a filesystem or if the disk is mounted.
 
 <h2 style="color:red;"> CAUTION: </h2>