diff --git a/weed/command/filer.go b/weed/command/filer.go
index 1ea334e61..017427335 100644
--- a/weed/command/filer.go
+++ b/weed/command/filer.go
@@ -59,7 +59,7 @@ func init() {
 	f.disableDirListing = cmdFiler.Flag.Bool("disableDirListing", false, "turn off directory listing")
 	f.maxMB = cmdFiler.Flag.Int("maxMB", 32, "split files larger than the limit")
 	f.dirListingLimit = cmdFiler.Flag.Int("dirListLimit", 100000, "limit sub dir listing size")
-	f.dataCenter = cmdFiler.Flag.String("dataCenter", "", "prefer to write to volumes in this data center")
+	f.dataCenter = cmdFiler.Flag.String("dataCenter", "", "prefer to read and write to volumes in this data center")
 	f.rack = cmdFiler.Flag.String("rack", "", "prefer to write to volumes in this rack")
 	f.disableHttp = cmdFiler.Flag.Bool("disableHttp", false, "disable http request, only gRpc operations are allowed")
 	f.cipher = cmdFiler.Flag.Bool("encryptVolumeData", false, "encrypt data on volume servers")