Merge pull request #77313 from lahinson/osdocs-10861-etcd-db-sizing-guidance

[OSDOCS-10861]: Adding database sizing requirements to etcd docs

Author: ShaunaDiaz

modules/etcd-increase-db.adoc

@@ -12,7 +12,9 @@ You might want to increase the disk quota if you encounter a `low space` alert.
 
 Another scenario where you might want to increase the disk quota is if you encounter an `excessive database growth` alert. This alert is a warning that the database might grow too large in the next four hours. In this scenario, consider increasing the disk quota so that you do not eventually encounter a `low space` alert and possible write fails. 
 
-When you increase the disk quota, the amount of space that you specify is not immediately reserved. Instead, etcd can grow to that size if needed. Ensure that etcd is running on a dedicated disk that is larger than the value that you specify for the disk quota.
+If you increase the disk quota, the disk space that you specify is not immediately reserved. Instead, etcd can grow to that size if needed. Ensure that etcd is running on a dedicated disk that is larger than the value that you specify for the disk quota. 
+
+For large etcd databases, the control plane nodes must have additional memory and storage. Because you must account for the API server cache, the minimum memory required is at least three times the configured size of the etcd database.
 
 :FeatureName: Increasing the database size for etcd
 include::snippets/technology-preview.adoc[]