diff --git a/website/pages/docs/disks/usage.mdx b/website/pages/docs/disks/usage.mdx
index 6bb033173..8e78204af 100644
--- a/website/pages/docs/disks/usage.mdx
+++ b/website/pages/docs/disks/usage.mdx
@@ -86,9 +86,10 @@ Vagrant.configure("2") do |config|
 end
 ```
 
-Note: VirtualBox only allows for up to 30 disks to be attached to a given SATA Controller,
-and this number includes the primary disk! Attempting to configure more than 30 will
-result in a Vagrant error.
+Note: VirtualBox has a hard limit on the number of disks that can be attached
+to a given storage controller, which is defined by the controller type.
+Attempting to configure more disks than are supported by the primary
+controller will result in a Vagrant error.
 
 ### Attaching optical drives
 
@@ -106,8 +107,8 @@ Vagrant.configure("2") do |config|
 end
 ```
 
-Note: VirtualBox only allows for up to 4 optical drives to be attached to a
-given IDE controller.
+As with hard disks, configuring more disks than are supported by your VM's
+storage controller arrangement will result in a Vagrant error.
 
 ### Removing Disks
 
diff --git a/website/pages/docs/disks/virtualbox/common-issues.mdx b/website/pages/docs/disks/virtualbox/common-issues.mdx
index db8a6dd7e..fdcd8aab5 100644
--- a/website/pages/docs/disks/virtualbox/common-issues.mdx
+++ b/website/pages/docs/disks/virtualbox/common-issues.mdx
@@ -21,10 +21,21 @@ you should see a list of disks attached to your guest.
 
 ## How many disks can I attach?
 
-Vagrant attaches all new disks defined to a guests SATA Controller. As of VirtualBox 6.1.x,
-SATA Controllers can only support up to **30 disks** per guest. Therefore if you try
-to define and attach more than 30, it will result in an error. This number _includes_
-the primary disk for the guest.
+Vagrant attaches all new disks defined to guest's primary controller. As of
+VirtualBox 6.1.x, storage controllers have the following limits to the number
+of disks that are supported per guest:
+
+- IDE Controllers: 4
+- SATA Controllers: 30
+- SCSI Controllers: 16
+
+Therefore if your primary disk is attached to a SATA Controller and you try to
+define and attach more than 30, it will result in an error. This number
+_includes_ the primary disk for the guest.
+
+DVD attachments are subject to the same limits.  Optical disk attachments will
+be attached to the storage controller with the highest boot priority (usually
+the IDE controller).
 
 ## Resizing VMDK format disks
 
diff --git a/website/pages/docs/disks/virtualbox/index.mdx b/website/pages/docs/disks/virtualbox/index.mdx
index 974efe76f..d6e71af95 100644
--- a/website/pages/docs/disks/virtualbox/index.mdx
+++ b/website/pages/docs/disks/virtualbox/index.mdx
@@ -34,9 +34,11 @@ to be applied.
 When new disks are defined to be attached to a guest, Vagrant will attach
 disks to a particular storage controller based on the type of disk configured:
 
-- For the `:disk` type, Vagrant will attach the disk to a guest's SATA
-  controller. It will also create the disk if necessary.
-- For the `:dvd` type, Vagrant will attach the disk to a guest's IDE
+- For the `:disk` type, Vagrant will use the storage controller containing the
+  boot disk. It will also create the disk if necessary.
+- For the `:dvd` type, Vagrant will attach the disk to the storage controller
+  that comes earliest in the machine's boot order. For example, if a VM has a
+  SATA controller and an IDE controller, the disk will be attached to the IDE
   controller.
 
 Vagrant will not be able to configure disks of a given type if the associated