Rules governing node root volumes and root aggregates
A node's root volume contains special directories and files for that node. The root aggregate contains the root volume. A few rules govern a node's root volume and root aggregate.
A node's root volume is a FlexVol volume that is installed at the factory or by setup software. It is reserved for system files, log files, and core files. The directory name is /mroot, which is accessible only through the systemshell by technical support. The minimum size for a node's root volume depends on the platform model.
The following rules govern the node's root volume:
Unless technical support instructs you to do so, do not modify the configuration or content of the root volume.
Do not store user data in the root volume.
Storing user data in the root volume increases the storage giveback time between nodes in an HA pair.
Starting with ONTAP 9.5, you can move the root volume to another aggregate.
The root aggregate is dedicated to the node's root volume only.
ONTAP prevents you from creating other volumes in the root aggregate.