Only attempt upgrade if update is ok.

pkg/cluster/cluster.go

@@ -780,8 +780,12 @@ func (c *Cluster) Update(oldSpec, newSpec *acidv1.Postgresql) error {
 		updateFailed = true
 	}
 
-	if err := c.majorVersionUpgrade(); err != nil {
-		c.logger.Errorf("major version upgrade failed: %v", err)
+	if !updateFailed {
+		// Major version upgrade must only fire after success of earlier operations and should stay last
+		if err := c.majorVersionUpgrade(); err != nil {
+			c.logger.Errorf("major version upgrade failed: %v", err)
+			updateFailed = true
+		}
 	}
 
 	return nil

pkg/cluster/sync.go

@@ -118,6 +118,7 @@ func (c *Cluster) Sync(newSpec *acidv1.Postgresql) error {
 		return fmt.Errorf("could not sync connection pooler: %v", err)
 	}
 
+	// Major version upgrade must only run after success of all earlier operations, must remain last item in sync
 	if err := c.majorVersionUpgrade(); err != nil {
 		c.logger.Errorf("major version upgrade failed: %v", err)
 	}