ec: fix variable shadowing and add -diskType to ec.rebuild and volumeServer.evacuate

Address code review comments:

1. Fix variable shadowing in collectEcVolumeServersByDc():
   - Rename loop variable 'diskType' to 'diskTypeKey' and 'diskTypeStr'
     to avoid shadowing the function parameter

2. Fix hardcoded HardDriveType in ecBalancer methods:
   - balanceEcRack(): use ecb.diskType instead of types.HardDriveType
   - collectVolumeIdToEcNodes(): use ecb.diskType

3. Add -diskType flag to ec.rebuild command:
   - Add diskType field to ecRebuilder struct
   - Pass diskType to collectEcNodes() and addEcVolumeShards()

4. Add -diskType flag to volumeServer.evacuate command:
   - Add diskType field to commandVolumeServerEvacuate struct
   - Pass diskType to collectEcVolumeServersByDc() and moveMountedShardToEcNode()

weed/shell/command_ec_common.go

@@ -439,17 +439,17 @@ func collectEcVolumeServersByDc(topo *master_pb.TopologyInfo, selectedDataCenter
 		// Build disk-level information from volumes and EC shards
 		// First, discover all unique disk IDs from VolumeInfos (includes empty disks)
 		allDiskIds := make(map[uint32]string) // diskId -> diskType
-		for diskType, diskInfo := range dn.DiskInfos {
+		for diskTypeKey, diskInfo := range dn.DiskInfos {
 			if diskInfo == nil {
 				continue
 			}
 			// Get all disk IDs from volumes
 			for _, vi := range diskInfo.VolumeInfos {
-				allDiskIds[vi.DiskId] = diskType
+				allDiskIds[vi.DiskId] = diskTypeKey
 			}
 			// Also get disk IDs from EC shards
 			for _, ecShardInfo := range diskInfo.EcShardInfos {
-				allDiskIds[ecShardInfo.DiskId] = diskType
+				allDiskIds[ecShardInfo.DiskId] = diskTypeKey
 			}
 		}
 
@@ -476,7 +476,7 @@ func collectEcVolumeServersByDc(topo *master_pb.TopologyInfo, selectedDataCenter
 		}
 		freePerDisk := int(freeEcSlots) / diskCount
 
-		for diskId, diskType := range allDiskIds {
+		for diskId, diskTypeStr := range allDiskIds {
 			shards := diskShards[diskId]
 			if shards == nil {
 				shards = make(map[needle.VolumeId]erasure_coding.ShardBits)
@@ -488,7 +488,7 @@ func collectEcVolumeServersByDc(topo *master_pb.TopologyInfo, selectedDataCenter
 
 			ecNode.disks[diskId] = &EcDisk{
 				diskId:       diskId,
-				diskType:     diskType,
+				diskType:     diskTypeStr,
 				freeEcSlots:  freePerDisk,
 				ecShardCount: totalShardCount,
 				ecShards:     shards,
@@ -928,7 +928,7 @@ func (ecb *ecBalancer) doBalanceEcRack(ecRack *EcRack) error {
 	}
 
 	ecNodeIdToShardCount := groupByCount(rackEcNodes, func(ecNode *EcNode) (id string, count int) {
-		diskInfo, found := ecNode.info.DiskInfos[string(types.HardDriveType)]
+		diskInfo, found := ecNode.info.DiskInfos[string(ecb.diskType)]
 		if !found {
 			return
 		}
@@ -956,12 +956,12 @@ func (ecb *ecBalancer) doBalanceEcRack(ecRack *EcRack) error {
 		if fullNodeShardCount > averageShardCount && emptyNodeShardCount+1 <= averageShardCount {
 
 			emptyNodeIds := make(map[uint32]bool)
-			if emptyDiskInfo, found := emptyNode.info.DiskInfos[string(types.HardDriveType)]; found {
+			if emptyDiskInfo, found := emptyNode.info.DiskInfos[string(ecb.diskType)]; found {
 				for _, shards := range emptyDiskInfo.EcShardInfos {
 					emptyNodeIds[shards.Id] = true
 				}
 			}
-			if fullDiskInfo, found := fullNode.info.DiskInfos[string(types.HardDriveType)]; found {
+			if fullDiskInfo, found := fullNode.info.DiskInfos[string(ecb.diskType)]; found {
 				for _, shards := range fullDiskInfo.EcShardInfos {
 					if _, found := emptyNodeIds[shards.Id]; !found {
 						for _, shardId := range erasure_coding.ShardBits(shards.EcIndexBits).ShardIds() {
@@ -1181,7 +1181,7 @@ func pickNEcShardsToMoveFrom(ecNodes []*EcNode, vid needle.VolumeId, n int, disk
 func (ecb *ecBalancer) collectVolumeIdToEcNodes(collection string) map[needle.VolumeId][]*EcNode {
 	vidLocations := make(map[needle.VolumeId][]*EcNode)
 	for _, ecNode := range ecb.ecNodes {
-		diskInfo, found := ecNode.info.DiskInfos[string(types.HardDriveType)]
+		diskInfo, found := ecNode.info.DiskInfos[string(ecb.diskType)]
 		if !found {
 			continue
 		}

weed/shell/command_ec_rebuild.go

@@ -25,6 +25,7 @@ type ecRebuilder struct {
 	writer       io.Writer
 	applyChanges bool
 	collections  []string
+	diskType     types.DiskType
 
 	ewg       *ErrorWaitGroup
 	ecNodesMu sync.Mutex
@@ -40,7 +41,7 @@ func (c *commandEcRebuild) Name() string {
 func (c *commandEcRebuild) Help() string {
 	return `find and rebuild missing ec shards among volume servers
 
-	ec.rebuild [-c EACH_COLLECTION|<collection_name>] [-apply] [-maxParallelization N]
+	ec.rebuild [-c EACH_COLLECTION|<collection_name>] [-apply] [-maxParallelization N] [-diskType=<disk_type>]
 
 	Options:
 	  -collection: specify a collection name, or "EACH_COLLECTION" to process all collections
@@ -48,6 +49,7 @@ func (c *commandEcRebuild) Help() string {
 	  -maxParallelization: number of volumes to rebuild concurrently (default: 10)
 	                       Increase for faster rebuilds with more system resources.
 	                       Decrease if experiencing resource contention or instability.
+	  -diskType: disk type for EC shards (hdd, ssd, or empty for default hdd)
 
 	Algorithm:
 
@@ -84,6 +86,7 @@ func (c *commandEcRebuild) Do(args []string, commandEnv *CommandEnv, writer io.W
 	collection := fixCommand.String("collection", "EACH_COLLECTION", "collection name, or \"EACH_COLLECTION\" for each collection")
 	maxParallelization := fixCommand.Int("maxParallelization", DefaultMaxParallelization, "run up to X tasks in parallel, whenever possible")
 	applyChanges := fixCommand.Bool("apply", false, "apply the changes")
+	diskTypeStr := fixCommand.String("diskType", "", "disk type for EC shards (hdd, ssd, or empty for default hdd)")
 	// TODO: remove this alias
 	applyChangesAlias := fixCommand.Bool("force", false, "apply the changes (alias for -apply)")
 	if err = fixCommand.Parse(args); err != nil {
@@ -96,8 +99,10 @@ func (c *commandEcRebuild) Do(args []string, commandEnv *CommandEnv, writer io.W
 		return
 	}
 
+	diskType := types.ToDiskType(*diskTypeStr)
+
 	// collect all ec nodes
-	allEcNodes, _, err := collectEcNodes(commandEnv, types.HardDriveType)
+	allEcNodes, _, err := collectEcNodes(commandEnv, diskType)
 	if err != nil {
 		return err
 	}
@@ -118,6 +123,7 @@ func (c *commandEcRebuild) Do(args []string, commandEnv *CommandEnv, writer io.W
 		writer:       writer,
 		applyChanges: *applyChanges,
 		collections:  collections,
+		diskType:     diskType,
 
 		ewg: NewErrorWaitGroup(*maxParallelization),
 	}
@@ -295,7 +301,7 @@ func (erb *ecRebuilder) rebuildOneEcVolume(collection string, volumeId needle.Vo
 	// ensure ECNode updates are atomic
 	erb.ecNodesMu.Lock()
 	defer erb.ecNodesMu.Unlock()
-	rebuilder.addEcVolumeShards(volumeId, collection, generatedShardIds, types.HardDriveType)
+	rebuilder.addEcVolumeShards(volumeId, collection, generatedShardIds, erb.diskType)
 
 	return nil
 }