Understanding node root volumes

A node's root volume contains special directories and configuration files for that node.

The root volume is installed at the factory on FAS systems and on V-Series systems ordered with disk shelves.

The directory name for a node's root volume is /mroot, which is accessible only through the systemshell and with guidance from technical support. The root volume is reserved for system files, log files, and core files. You should not store user data in the root volume. Also, you must not change the preconfigured size for the root volume or modify the content of the root directory, unless technical support instructs you to do so. If you need to modify system configurations, you use Data ONTAP commands to do so instead of editing configuration files directly in the root directory.

You cannot set the root volume's fractional reserve to any value other than 100%.

The root aggregate contains the root volume. Starting with Data ONTAP 8.1, new systems are shipped with the root volume in a dedicated, 64-bit root aggregate that contains at least three disks. The root aggregate should contain only the root volume. You must not include or create data volumes in the root aggregate.

By default, the storage system is set up to use a hard disk drive (HDD) aggregate for the root aggregate. When no HDDs are available, the system is set up to use a solid-state drive (SSD) aggregate for the root aggregate.

You should contact technical support if you need to designate a different volume to be the new root volume or move the root volume to another aggregate.