<p>In a scenario where a zone/dc dropped and 2 master nodes out of 5 are now offline, I would like to restore etcd on the remaining 3 master nodes.</p>
<p>So far the best I could manage was restoring from etcd backup, but I found myself needing to destroy the remaining 2 and recreating them. Otherwise, I got a split brain issue.</p>
<p>Is there a way to remove the 2 dropped members from etcd and restore quorum for the remaining 3?</p>
<p>(OKD 4.7)</p>

<p>As per this <a href="https://platform9.com/kb/kubernetes/restore-etcd-cluster-from-quorum-loss" rel="nofollow noreferrer">doc</a> by Platform9.</p>
<p><strong>Restoring ETCD Backup to Recover Cluster From Loss of Quorum</strong>:</p>
<p>Master nodes going offline or a lack of connectivity between the master nodes leading to an unhealthy cluster state could cause a loss of quorum.</p>
<blockquote>
<p>The idea behind Etcd restore is to restore Etcd from a backup using
etcdctl and reduce the master count to 1. In order for it to start up
as a brand-new etcd cluster once that is finished, we may need to
manually make some adjustments. When things are back up, we increment
the expert count individually for example join hubs.</p>
<p>If the master nodes are hard offline or unreachable after restoring
from the etcd backup, proceed with deauthorizing the nodes as well.
From Kubectl perspective, the detached master nodes will be seen to be
in &quot;NotReady&quot; state. Delete these nodes from the cluster.</p>
<p>At this point, the cluster should be back up and running with a single
master node. Verify the same</p>
<p>Once the nodes are scaled back up, they should have a PMK stack
running on them which will ensure ETCD members will sync amongst each
other.</p>
</blockquote>
<p>Refer to this <a href="https://docs.openshift.com/container-platform/3.11/admin_guide/assembly_restore-etcd-quorum.html" rel="nofollow noreferrer">doc 1</a> and <a href="https://docs.openshift.com/container-platform/4.8/backup_and_restore/control_plane_backup_and_restore/replacing-unhealthy-etcd-member.html" rel="nofollow noreferrer">doc 2</a> by Red hat  for more information about Restoring etcd quorum and   Replacing an unhealthy etcd member</p>
