diff --git a/chain/consensus/filcns/upgrades.go b/chain/consensus/filcns/upgrades.go
index 2f8438b10..f3345ea7d 100644
--- a/chain/consensus/filcns/upgrades.go
+++ b/chain/consensus/filcns/upgrades.go
@@ -4,7 +4,9 @@ import (
 	"context"
 	_ "embed"
 	"fmt"
+	"os"
 	"runtime"
+	"strconv"
 	"time"
 
 	"github.com/docker/go-units"
@@ -53,6 +55,29 @@ import (
 //go:embed FVMLiftoff.txt
 var fvmLiftoffBanner string
 
+var (
+	MigrationMaxWorkerCount    int
+	EnvMigrationMaxWorkerCount = "LOTUS_MIGRATION_MAX_WORKER_COUNT"
+)
+
+func init() {
+	// the default calculation used for migration worker count
+	MigrationMaxWorkerCount = runtime.NumCPU()
+	// check if an alternative value was request by environment
+	if mwcs := os.Getenv(EnvMigrationMaxWorkerCount); mwcs != "" {
+		mwc, err := strconv.ParseInt(mwcs, 10, 32)
+		if err != nil {
+			log.Warnf("invalid value for %s (%s) defaulting to %d: %s", EnvMigrationMaxWorkerCount, mwcs, MigrationMaxWorkerCount, err)
+			return
+		}
+		// use value from environment
+		log.Infof("migration worker cound set from %s (%d)", EnvMigrationMaxWorkerCount, mwc)
+		MigrationMaxWorkerCount = int(mwc)
+		return
+	}
+	log.Infof("migration worker count: %d", MigrationMaxWorkerCount)
+}
+
 func DefaultUpgradeSchedule() stmgr.UpgradeSchedule {
 	var us stmgr.UpgradeSchedule
 
@@ -891,7 +916,7 @@ func UpgradeCalico(ctx context.Context, sm *stmgr.StateManager, _ stmgr.Migratio
 
 func UpgradeActorsV3(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, cb stmgr.ExecMonitor, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
 	// Use all the CPUs except 3.
-	workerCount := runtime.NumCPU() - 3
+	workerCount := MigrationMaxWorkerCount - 3
 	if workerCount <= 0 {
 		workerCount = 1
 	}
@@ -929,7 +954,7 @@ func UpgradeActorsV3(ctx context.Context, sm *stmgr.StateManager, cache stmgr.Mi
 
 func PreUpgradeActorsV3(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) error {
 	// Use half the CPUs for pre-migration, but leave at least 3.
-	workerCount := runtime.NumCPU()
+	workerCount := MigrationMaxWorkerCount
 	if workerCount <= 4 {
 		workerCount = 1
 	} else {
@@ -993,7 +1018,7 @@ func upgradeActorsV3Common(
 
 func UpgradeActorsV4(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, cb stmgr.ExecMonitor, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
 	// Use all the CPUs except 3.
-	workerCount := runtime.NumCPU() - 3
+	workerCount := MigrationMaxWorkerCount - 3
 	if workerCount <= 0 {
 		workerCount = 1
 	}
@@ -1015,7 +1040,7 @@ func UpgradeActorsV4(ctx context.Context, sm *stmgr.StateManager, cache stmgr.Mi
 
 func PreUpgradeActorsV4(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) error {
 	// Use half the CPUs for pre-migration, but leave at least 3.
-	workerCount := runtime.NumCPU()
+	workerCount := MigrationMaxWorkerCount
 	if workerCount <= 4 {
 		workerCount = 1
 	} else {
@@ -1079,7 +1104,7 @@ func upgradeActorsV4Common(
 
 func UpgradeActorsV5(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, cb stmgr.ExecMonitor, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
 	// Use all the CPUs except 3.
-	workerCount := runtime.NumCPU() - 3
+	workerCount := MigrationMaxWorkerCount - 3
 	if workerCount <= 0 {
 		workerCount = 1
 	}
@@ -1101,7 +1126,7 @@ func UpgradeActorsV5(ctx context.Context, sm *stmgr.StateManager, cache stmgr.Mi
 
 func PreUpgradeActorsV5(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) error {
 	// Use half the CPUs for pre-migration, but leave at least 3.
-	workerCount := runtime.NumCPU()
+	workerCount := MigrationMaxWorkerCount
 	if workerCount <= 4 {
 		workerCount = 1
 	} else {
@@ -1165,7 +1190,7 @@ func upgradeActorsV5Common(
 
 func UpgradeActorsV6(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, cb stmgr.ExecMonitor, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
 	// Use all the CPUs except 3.
-	workerCount := runtime.NumCPU() - 3
+	workerCount := MigrationMaxWorkerCount - 3
 	if workerCount <= 0 {
 		workerCount = 1
 	}
@@ -1187,7 +1212,7 @@ func UpgradeActorsV6(ctx context.Context, sm *stmgr.StateManager, cache stmgr.Mi
 
 func PreUpgradeActorsV6(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) error {
 	// Use half the CPUs for pre-migration, but leave at least 3.
-	workerCount := runtime.NumCPU()
+	workerCount := MigrationMaxWorkerCount
 	if workerCount <= 4 {
 		workerCount = 1
 	} else {
@@ -1251,7 +1276,7 @@ func upgradeActorsV6Common(
 
 func UpgradeActorsV7(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, cb stmgr.ExecMonitor, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
 	// Use all the CPUs except 3.
-	workerCount := runtime.NumCPU() - 3
+	workerCount := MigrationMaxWorkerCount - 3
 	if workerCount <= 0 {
 		workerCount = 1
 	}
@@ -1273,7 +1298,7 @@ func UpgradeActorsV7(ctx context.Context, sm *stmgr.StateManager, cache stmgr.Mi
 
 func PreUpgradeActorsV7(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) error {
 	// Use half the CPUs for pre-migration, but leave at least 3.
-	workerCount := runtime.NumCPU()
+	workerCount := MigrationMaxWorkerCount
 	if workerCount <= 4 {
 		workerCount = 1
 	} else {
@@ -1344,7 +1369,7 @@ func upgradeActorsV7Common(
 
 func UpgradeActorsV8(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, cb stmgr.ExecMonitor, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
 	// Use all the CPUs except 3.
-	workerCount := runtime.NumCPU() - 3
+	workerCount := MigrationMaxWorkerCount - 3
 	if workerCount <= 0 {
 		workerCount = 1
 	}
@@ -1368,7 +1393,7 @@ func UpgradeActorsV8(ctx context.Context, sm *stmgr.StateManager, cache stmgr.Mi
 
 func PreUpgradeActorsV8(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) error {
 	// Use half the CPUs for pre-migration, but leave at least 3.
-	workerCount := runtime.NumCPU()
+	workerCount := MigrationMaxWorkerCount
 	if workerCount <= 4 {
 		workerCount = 1
 	} else {
@@ -1451,7 +1476,7 @@ func upgradeActorsV8Common(
 func UpgradeActorsV9(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, cb stmgr.ExecMonitor,
 	root cid.Cid, epoch abi.ChainEpoch, ts *types.TipSet) (cid.Cid, error) {
 	// Use all the CPUs except 3.
-	workerCount := runtime.NumCPU() - 3
+	workerCount := MigrationMaxWorkerCount - 3
 	if workerCount <= 0 {
 		workerCount = 1
 	}
@@ -1474,7 +1499,7 @@ func UpgradeActorsV9(ctx context.Context, sm *stmgr.StateManager, cache stmgr.Mi
 func PreUpgradeActorsV9(ctx context.Context, sm *stmgr.StateManager, cache stmgr.MigrationCache, root cid.Cid,
 	epoch abi.ChainEpoch, ts *types.TipSet) error {
 	// Use half the CPUs for pre-migration, but leave at least 3.
-	workerCount := runtime.NumCPU()
+	workerCount := MigrationMaxWorkerCount
 	if workerCount <= 4 {
 		workerCount = 1
 	} else {