Merge pull request #43010 from jldohmann/BZ2006015

BZ2006015: etcd snapshot is non blocking

Author: EricPonvelle

backup_and_restore/control_plane_backup_and_restore/backing-up-etcd.adoc

@@ -13,8 +13,8 @@ Back up your cluster's etcd data regularly and store in a secure location
 ideally outside the {product-title} 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.
+recommended to take etcd backups during non-peak usage hours, because the etcd snapshot has a high I/O cost.
+
 
 Be sure to take an etcd backup after you upgrade your cluster. This is important because when you restore your cluster, you must use an etcd backup that was taken from the same z-stream release. For example, an {product-title} 4.y.z cluster must use an etcd backup that was taken from 4.y.z.