Merge pull request docker#7754 from ollypom/3.1-system-requirements

Update storage requirements for UCP 3.1

Author: bermudezmt

ee/ucp/admin/install/system-requirements.md

@@ -22,8 +22,8 @@ You can install UCP on-premises or on a cloud provider. Common requirements:
 
 * 8GB of RAM for manager nodes
 * 4GB of RAM for worker nodes
-* 4GiB of free disk space for the root partition for manager nodes
-* 500MiB of free disk space for the root partition for worker nodes
+* 4GB of free disk space for the `/var` partition for manager nodes
+* 500MB of free disk space for the `/var` partition for worker nodes
 
 ### Recommended production requirements
 

ee/ucp/release-notes.md

@@ -98,6 +98,8 @@ There are several backward-incompatible changes in the Kubernetes API that may a
 
 * Pod Security Policies are not supported in this release. (#15105)
 
+* The default Kubelet configuration for UCP Manager nodes is expecting 4GB of free disk space in the `/var` partition. See [System Requirements](/ee/ucp/admin/install/system-requirements) for details.
+
 ## Deprecated features
 
 The following features are deprecated in UCP 3.1.