Q:

No create/update access for object when importing records from CSV via Salesforce CLI

I've been testing to insert a custom metadata type record from a CSV file via Salesforce CLI. I've used below command but I've been getting the following error: 
Command 
sfdx force:data:bulk:upsert -i Id -f cmdt.csv -s Mapping__mdt -u newuser@salesforce.org
Error

No create/update access for object: Mapping__mdt

Please take note that I use the System Administrator profile, so I am expecting that I have the right access.
It is my first time loading custom metadata type records via CLI, hoping to incorporate Salesforce DX technology in my present and future implementations. Would like to ask for your help regarding this.

A:

Custom Metadata is metadata, meaning you can't use normal data import methods. Use force:source:retrieve to get the contents of Custom Metadata, and force:source:deploy to deploy the metadata. See CustomMetadata for more information on what the files look like.

