readme: remove reference to old backup/restore

README.md

@@ -20,8 +20,7 @@ The etcd operator manages etcd clusters deployed to [Kubernetes][k8s-home] and a
 
 - [Create and destroy](#create-and-destroy-an-etcd-cluster)
 - [Resize](#resize-an-etcd-cluster)
-- [Recover a member](#member-recovery)
-- [Backup and restore a cluster](#disaster-recovery)
+- [Failure recovery](#failure-recovery)
 - [Rolling upgrade](#upgrade-an-etcd-cluster)
 
 There are [more spec examples](./doc/user/spec_examples.md) on setting up clusters with backup, restore, and other configurations.
@@ -143,7 +142,7 @@ example-etcd-cluster-0003       1/1       Running   0          1m
 example-etcd-cluster-0004       1/1       Running   0          1m
 ```
 
-## Member recovery
+## Failure Recovery
 
 If the minority of etcd members crash, the etcd operator will automatically recover the failure.
 Let's walk through in the following steps.
@@ -207,79 +206,6 @@ example-etcd-cluster-0002       1/1       Running   0          1m
 example-etcd-cluster-0003       1/1       Running   0          1m
 ```
 
-## Disaster recovery
-
-> 🚨 Backup is currently only supported with etcd v3 API data. Any data stored using the etcd v2 API will **not** be backed up.
-
-If the majority of etcd members crash, but at least one backup exists for the cluster, the etcd operator can restore the entire cluster from the backup.
-
-Before creating a backup enabled cluster you will need a storage class for the backup spec. For example create a storage class that provisions a GCEPersistentDisk:
-
-```
-$ kubectl create -f example/example-storage-class-gce-pd.yaml
-$ kubectl get storageclass
-NAME                 TYPE
-etcd-backup-gce-pd   kubernetes.io/gce-pd
-```
-
-This is used to request the persistent volume to store the backup data. See [other backup options](doc/user/backup_config.md).
-
-To enable backup, create an etcd cluster with [backup enabled spec](example/example-etcd-cluster-with-backup.yaml) that specifies the above storage class name.
-
-```
-$ kubectl create -f example/example-etcd-cluster-with-backup.yaml
-```
-
-A persistent volume claim is created for the backup pod:
-
-```
-$ kubectl get pvc
-NAME                                   STATUS    VOLUME                                     CAPACITY   ACCESSMODES   AGE
-example-etcd-cluster-with-backup-pvc   Bound     pvc-79e39bab-b973-11e6-8ae4-42010af00002   1Gi        RWO           9s
-```
-
-Let's try to write some data into etcd:
-
-```
-$ kubectl run --rm -i --tty fun --image quay.io/coreos/etcd --restart=Never -- /bin/sh
-/ # ETCDCTL_API=3 etcdctl --endpoints http://example-etcd-cluster-with-backup-client:2379 put foo bar
-OK
-(ctrl-D to exit)
-```
-
-Now let's kill two pods to simulate a disaster failure:
-
-```
-$ kubectl delete pod example-etcd-cluster-with-backup-0000 example-etcd-cluster-with-backup-0001 --now
-pod "example-etcd-cluster-with-backup-0000" deleted
-pod "example-etcd-cluster-with-backup-0001" deleted
-```
-
-Now quorum is lost. The etcd operator will start to recover the cluster by:
-- Creating a new seed member to recover from the backup
-- Add more members until the size reaches to specified number
-
-```
-$ kubectl get pods
-NAME                                                    READY     STATUS     RESTARTS   AGE
-example-etcd-cluster-with-backup-0003                   0/1       Init:0/2   0          11s
-example-etcd-cluster-with-backup-backup-sidecar-e9gkv   1/1       Running    0          18m
-...
-$ kubectl get pods
-NAME                                                    READY     STATUS    RESTARTS   AGE
-example-etcd-cluster-with-backup-0003                   1/1       Running   0          3m
-example-etcd-cluster-with-backup-0004                   1/1       Running   0          3m
-example-etcd-cluster-with-backup-0005                   1/1       Running   0          3m
-example-etcd-cluster-with-backup-backup-sidecar-e9gkv   1/1       Running   0          22m
-```
-
-Finally, besides destroying the cluster, also cleanup the backup if you don't need it anymore:
-```
-$ kubectl delete pvc example-etcd-cluster-with-backup-pvc
-```
-
-Note: There could be a race that it will fall to single member recovery if a pod is recovered before another is deleted.
-
 ## Upgrade an etcd cluster
 
 Have the following yaml file ready:
@@ -345,10 +271,6 @@ Check the other two pods and you should see the same result.
 
 - The etcd operator only manages the etcd cluster created in the same namespace. Users need to create multiple operators in different namespaces to manage etcd clusters in different namespaces.
 
-- Backup works only for data in etcd3 storage, not for data in etcd2 storage.
-
-- PV Backup only works on GCE(kubernetes.io/gce-pd) and AWS(kubernetes.io/aws-ebs) for now.
-
 - Migration, the process of allowing the etcd operator to manage existing etcd3 clusters, only supports a single-member cluster, with its node running in the same Kubernetes cluster.