diff --git a/weed/shell/command_ec_common.go b/weed/shell/command_ec_common.go
index a6f714a0d..4c3b7459c 100644
--- a/weed/shell/command_ec_common.go
+++ b/weed/shell/command_ec_common.go
@@ -1628,11 +1628,16 @@ func EcBalance(commandEnv *CommandEnv, collections []string, dc string, ecReplic
 
 // compileCollectionPattern compiles a regex pattern for collection matching.
 // Empty patterns match empty collections only.
+// The special keyword CollectionDefault ("_default") matches empty collections.
 func compileCollectionPattern(pattern string) (*regexp.Regexp, error) {
 	if pattern == "" {
 		// empty pattern matches empty collection
 		return regexp.Compile("^$")
 	}
+	if pattern == CollectionDefault {
+		// CollectionDefault keyword matches empty collection
+		return regexp.Compile("^$")
+	}
 	return regexp.Compile(pattern)
 }
 
diff --git a/weed/shell/command_volume_configure_replication.go b/weed/shell/command_volume_configure_replication.go
index c54efd05c..74d20eb93 100644
--- a/weed/shell/command_volume_configure_replication.go
+++ b/weed/shell/command_volume_configure_replication.go
@@ -116,10 +116,19 @@ func getVolumeFilter(replicaPlacement *super_block.ReplicaPlacement, volumeId ui
 		}
 	}
 	return func(v *master_pb.VolumeInformationMessage) bool {
-		matched, err := filepath.Match(collectionPattern, v.Collection)
-		if err != nil {
-			return false
+		var collectionMatched bool
+		if collectionPattern == "" {
+			// Empty pattern matches all collections
+			collectionMatched = true
+		} else if collectionPattern == CollectionDefault {
+			collectionMatched = v.Collection == ""
+		} else {
+			m, err := filepath.Match(collectionPattern, v.Collection)
+			if err != nil {
+				return false
+			}
+			collectionMatched = m
 		}
-		return matched
+		return collectionMatched && v.ReplicaPlacement != replicaPlacementInt32
 	}
 }
diff --git a/weed/shell/command_volume_fix_replication.go b/weed/shell/command_volume_fix_replication.go
index 9c760ef9d..574579c34 100644
--- a/weed/shell/command_volume_fix_replication.go
+++ b/weed/shell/command_volume_fix_replication.go
@@ -268,9 +268,15 @@ func (c *commandVolumeFixReplication) deleteOneVolume(commandEnv *CommandEnv, wr
 
 		// check collection name pattern
 		if *c.collectionPattern != "" {
-			matched, err := filepath.Match(*c.collectionPattern, replica.info.Collection)
-			if err != nil {
-				return fmt.Errorf("match pattern %s with collection %s: %v", *c.collectionPattern, replica.info.Collection, err)
+			var matched bool
+			if *c.collectionPattern == CollectionDefault {
+				matched = replica.info.Collection == ""
+			} else {
+				var err error
+				matched, err = filepath.Match(*c.collectionPattern, replica.info.Collection)
+				if err != nil {
+					return fmt.Errorf("match pattern %s with collection %s: %v", *c.collectionPattern, replica.info.Collection, err)
+				}
 			}
 			if !matched {
 				continue
@@ -357,9 +363,15 @@ func (c *commandVolumeFixReplication) fixOneUnderReplicatedVolume(commandEnv *Co
 		if fn(dst.dataNode) > 0 && satisfyReplicaPlacement(replicaPlacement, replicas, dst) {
 			// check collection name pattern
 			if *c.collectionPattern != "" {
-				matched, err := filepath.Match(*c.collectionPattern, replica.info.Collection)
-				if err != nil {
-					return fmt.Errorf("match pattern %s with collection %s: %v", *c.collectionPattern, replica.info.Collection, err)
+				var matched bool
+				if *c.collectionPattern == CollectionDefault {
+					matched = replica.info.Collection == ""
+				} else {
+					var err error
+					matched, err = filepath.Match(*c.collectionPattern, replica.info.Collection)
+					if err != nil {
+						return fmt.Errorf("match pattern %s with collection %s: %v", *c.collectionPattern, replica.info.Collection, err)
+					}
 				}
 				if !matched {
 					hasSkippedCollection = true
diff --git a/weed/shell/command_volume_list.go b/weed/shell/command_volume_list.go
index 04573d402..956d372bb 100644
--- a/weed/shell/command_volume_list.go
+++ b/weed/shell/command_volume_list.go
@@ -202,7 +202,13 @@ func (c *commandVolumeList) isNotMatchDiskInfo(readOnly bool, collection string,
 		return true
 	}
 	if *c.collectionPattern != "" {
-		if matched, _ := filepath.Match(*c.collectionPattern, collection); !matched {
+		var matched bool
+		if *c.collectionPattern == CollectionDefault {
+			matched = (collection == "")
+		} else {
+			matched, _ = filepath.Match(*c.collectionPattern, collection)
+		}
+		if !matched {
 			return true
 		}
 	}
diff --git a/weed/shell/command_volume_tier_move.go b/weed/shell/command_volume_tier_move.go
index cfa2eaef3..b0f9cba12 100644
--- a/weed/shell/command_volume_tier_move.go
+++ b/weed/shell/command_volume_tier_move.go
@@ -50,6 +50,10 @@ func (c *commandVolumeTierMove) Help() string {
 	Even if the volume is replicated, only one replica will be changed and the rest replicas will be dropped.
 	So "volume.fix.replication" and "volume.balance" should be followed.
 
+	Note:
+		Use -collectionPattern="_default" to match only the default collection (volumes with no collection name).
+		Empty collectionPattern matches all collections.
+
 `
 }
 
@@ -310,9 +314,16 @@ func collectVolumeIdsForTierChange(topologyInfo *master_pb.TopologyInfo, volumeS
 			for _, v := range diskInfo.VolumeInfos {
 				// check collection name pattern
 				if collectionPattern != "" {
-					matched, err := filepath.Match(collectionPattern, v.Collection)
-					if err != nil {
-						return
+					var matched bool
+					if collectionPattern == CollectionDefault {
+						matched = v.Collection == ""
+					} else {
+						var matchErr error
+						matched, matchErr = filepath.Match(collectionPattern, v.Collection)
+						if matchErr != nil {
+							err = fmt.Errorf("collection pattern %q failed to match: %w", collectionPattern, matchErr)
+							return
+						}
 					}
 					if !matched {
 						continue
@@ -328,6 +339,11 @@ func collectVolumeIdsForTierChange(topologyInfo *master_pb.TopologyInfo, volumeS
 		}
 	})
 
+	// Check if an error occurred during iteration and return early
+	if err != nil {
+		return
+	}
+
 	for vid := range vidMap {
 		vids = append(vids, needle.VolumeId(vid))
 	}
diff --git a/weed/shell/common.go b/weed/shell/common.go
index cb2df5828..922cd5316 100644
--- a/weed/shell/common.go
+++ b/weed/shell/common.go
@@ -9,6 +9,9 @@ import (
 var (
 	// Default maximum parallelization/concurrency for commands supporting it.
 	DefaultMaxParallelization = 10
+	// CollectionDefault is the special keyword to match empty collection names.
+	// Use "_default" to avoid collision with a literal collection named "default".
+	CollectionDefault = "_default"
 )
 
 // ErrorWaitGroup implements a goroutine wait group which aggregates errors, if any.