Backing up etcd data

Backing up etcd data

etcd is the key-value store for OpenShift Container Platform, which persists the state of all resource objects.

Back up your cluster’s etcd data regularly and store in a secure location ideally outside the OpenShift Container Platform environment. Do not take an etcd backup before the first certificate rotation completes, which occurs 24 hours after installation, otherwise the backup will contain expired certificates. It is also recommended to take etcd backups during non-peak usage hours, as it is a blocking action.

Once you have an etcd backup, you can recover from lost master hosts and restore to a previous cluster state.

You can perform the etcd data backup process on any master host that has connectivity to the etcd cluster, where the proper certificates are provided.

Follow these steps to back up etcd data by creating a snapshot. This snapshot can be saved and used at a later time if you need to restore etcd.

You should only save a snapshot from a single master host. You do not need a snapshot from each master host in the cluster.

Prerequisites

SSH access to a master host.

Procedure

Access a master host.
If the cluster-wide proxy is enabled, be sure that you have exported the NO_PROXY, HTTP_PROXY, and HTTPS_PROXY environment variables.

You can check whether the proxy is enabled by reviewing the output of oc get proxy cluster -o yaml. The proxy is enabled if the httpProxy, httpsProxy, and noProxy fields have values set.
Run the etcd-snapshot-backup.sh script and pass in the location to save the etcd snapshot to.

Be sure to pass in the -E flag to sudo so that environment variables are properly passed to the script.
```
$ sudo -E /usr/local/bin/etcd-snapshot-backup.sh ./assets/backup/snapshot.db
```
In this example, the snapshot is saved to ./assets/backup/snapshot.db on the master host.