remove older deploymentID fix behavior to speed up startup (#19497)

since mid 2018 we do not have any deployments
without deployment-id, it is time to put this
code to rest, this PR removes this old code as
its no longer valuable.

on setups with 1000's of drives these are all
quite expensive operations.

cmd/xl-storage.go

@@ -407,12 +407,6 @@ func (s *xlStorage) GetDiskLoc() (poolIdx, setIdx, diskIdx int) {
 	return s.endpoint.PoolIdx, s.endpoint.SetIdx, s.endpoint.DiskIdx
 }
 
-func (s *xlStorage) SetFormatData(b []byte) {
-	s.Lock()
-	defer s.Unlock()
-	s.formatData = b
-}
-
 func (s *xlStorage) Healing() *healingTracker {
 	healingFile := pathJoin(s.drivePath, minioMetaBucket,
 		bucketMetaPrefix, healingTrackerFilename)
@@ -2201,7 +2195,7 @@ func (s *xlStorage) writeAll(ctx context.Context, volume string, path string, b
 
 	var w *os.File
 	if sync {
-		// Perform directIO along with fdatasync for larger xl.meta, mostly when
+		// Perform DirectIO along with fdatasync for larger xl.meta, mostly when
 		// xl.meta has "inlined data" we prefer writing O_DIRECT and then doing
 		// fdatasync() at the end instead of opening the file with O_DSYNC.
 		//
@@ -2241,6 +2235,14 @@ func (s *xlStorage) writeAll(ctx context.Context, volume string, path string, b
 }
 
 func (s *xlStorage) WriteAll(ctx context.Context, volume string, path string, b []byte) (err error) {
+	// Specific optimization to avoid re-read from the drives for `format.json`
+	// in-case the caller is a network operation.
+	if volume == minioMetaBucket && path == formatConfigFile {
+		s.Lock()
+		s.formatData = b
+		s.Unlock()
+	}
+
 	return s.writeAll(ctx, volume, path, b, true)
 }