diff --git a/internal/caches/errors.go b/internal/caches/errors.go
index a0d986c..0fb8e75 100644
--- a/internal/caches/errors.go
+++ b/internal/caches/errors.go
@@ -12,7 +12,7 @@ var (
 	ErrEntityTooLarge     = errors.New("entity too large")
 	ErrWritingUnavailable = errors.New("writing unavailable")
 	ErrWritingQueueFull   = errors.New("writing queue full")
-	ErrTooManyOpenFiles   = errors.New("too many open files")
+	ErrServerIsBusy       = errors.New("server is busy")
 )
 
 // CapacityError 容量错误
@@ -38,7 +38,7 @@ func CanIgnoreErr(err error) bool {
 		err == ErrEntityTooLarge ||
 		err == ErrWritingUnavailable ||
 		err == ErrWritingQueueFull ||
-		err == ErrTooManyOpenFiles {
+		err == ErrServerIsBusy {
 		return true
 	}
 	_, ok := err.(*CapacityError)
diff --git a/internal/caches/max_open_files.go b/internal/caches/max_open_files.go
deleted file mode 100644
index c911230..0000000
--- a/internal/caches/max_open_files.go
+++ /dev/null
@@ -1,52 +0,0 @@
-// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved. Official site: https://goedge.cn .
-
-package caches
-
-import (
-	"github.com/TeaOSLab/EdgeNode/internal/goman"
-	"sync/atomic"
-	"time"
-)
-
-const (
-	modeSlow int32 = 1
-	modeFast int32 = 2
-)
-
-// MaxOpenFiles max open files manager
-type MaxOpenFiles struct {
-	ticker *time.Ticker
-	mode   int32
-}
-
-func NewMaxOpenFiles() *MaxOpenFiles {
-	var f = &MaxOpenFiles{}
-	f.ticker = time.NewTicker(1 * time.Second)
-	f.init()
-	return f
-}
-
-func (this *MaxOpenFiles) init() {
-	goman.New(func() {
-		for range this.ticker.C {
-			// reset mode
-			atomic.StoreInt32(&this.mode, modeFast)
-		}
-	})
-}
-
-func (this *MaxOpenFiles) Fast() {
-	atomic.AddInt32(&this.mode, modeFast)
-}
-
-func (this *MaxOpenFiles) FinishAll() {
-	this.Fast()
-}
-
-func (this *MaxOpenFiles) Slow() {
-	atomic.StoreInt32(&this.mode, modeSlow)
-}
-
-func (this *MaxOpenFiles) Next() bool {
-	return atomic.LoadInt32(&this.mode) != modeSlow
-}
diff --git a/internal/caches/max_open_files_test.go b/internal/caches/max_open_files_test.go
deleted file mode 100644
index 2b37ab4..0000000
--- a/internal/caches/max_open_files_test.go
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright 2022 Liuxiangchao iwind.liu@gmail.com. All rights reserved. Official site: https://goedge.cn .
-
-package caches_test
-
-import (
-	"github.com/TeaOSLab/EdgeNode/internal/caches"
-	"testing"
-	"time"
-)
-
-func TestNewMaxOpenFiles(t *testing.T) {
-	var maxOpenFiles = caches.NewMaxOpenFiles()
-	maxOpenFiles.Fast()
-	t.Log("fast:", maxOpenFiles.Next())
-
-	maxOpenFiles.Slow()
-	t.Log("slow:", maxOpenFiles.Next())
-	time.Sleep(1*time.Second + 1*time.Millisecond)
-	t.Log("slow 1 second:", maxOpenFiles.Next())
-
-	maxOpenFiles.Slow()
-	t.Log("slow:", maxOpenFiles.Next())
-
-	maxOpenFiles.Slow()
-	t.Log("slow:", maxOpenFiles.Next())
-
-	time.Sleep(1 * time.Second)
-	t.Log("slow 1 second:", maxOpenFiles.Next())
-
-	maxOpenFiles.Slow()
-	t.Log("slow:", maxOpenFiles.Next())
-
-	maxOpenFiles.Fast()
-	t.Log("fast:", maxOpenFiles.Next())
-}
diff --git a/internal/caches/storage_file.go b/internal/caches/storage_file.go
index 36d9b99..99624b1 100644
--- a/internal/caches/storage_file.go
+++ b/internal/caches/storage_file.go
@@ -61,9 +61,6 @@ const (
 var sharedWritingFileKeyMap = map[string]zero.Zero{} // key => bool
 var sharedWritingFileKeyLocker = sync.Mutex{}
 
-var maxOpenFiles = NewMaxOpenFiles()
-
-const maxOpenFilesSlowCost = 1000 * time.Microsecond // us
 const protectingLoadWhenDump = false
 
 // FileStorage 文件缓存
@@ -445,9 +442,9 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, hea
 		return nil, ErrFileIsWriting
 	}
 
-	if !isFlushing && !maxOpenFiles.Next() {
+	if !isFlushing && !fsutils.WriteReady() {
 		sharedWritingFileKeyLocker.Unlock()
-		return nil, ErrTooManyOpenFiles
+		return nil, ErrServerIsBusy
 	}
 
 	sharedWritingFileKeyMap[key] = zero.New()
@@ -456,9 +453,6 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, hea
 		if !isOk {
 			sharedWritingFileKeyLocker.Lock()
 			delete(sharedWritingFileKeyMap, key)
-			if len(sharedWritingFileKeyMap) == 0 {
-				maxOpenFiles.FinishAll()
-			}
 			sharedWritingFileKeyLocker.Unlock()
 		}
 	}()
@@ -558,7 +552,6 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, hea
 	if isNewCreated && existsFile {
 		flags |= os.O_TRUNC
 	}
-	var before = time.Now()
 	writer, err := os.OpenFile(tmpPath, flags, 0666)
 	if err != nil {
 		// TODO 检查在各个系统中的稳定性
@@ -572,13 +565,6 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, hea
 			return nil, err
 		}
 	}
-	if !isFlushing {
-		if time.Since(before) >= maxOpenFilesSlowCost {
-			maxOpenFiles.Slow()
-		} else {
-			maxOpenFiles.Fast()
-		}
-	}
 
 	var removeOnFailure = true
 	defer func() {
@@ -639,18 +625,12 @@ func (this *FileStorage) openWriter(key string, expiredAt int64, status int, hea
 		return NewPartialFileWriter(writer, key, expiredAt, metaHeaderSize, metaBodySize, isNewCreated, isPartial, partialBodyOffset, partialRanges, func() {
 			sharedWritingFileKeyLocker.Lock()
 			delete(sharedWritingFileKeyMap, key)
-			if len(sharedWritingFileKeyMap) == 0 {
-				maxOpenFiles.FinishAll()
-			}
 			sharedWritingFileKeyLocker.Unlock()
 		}), nil
 	} else {
 		return NewFileWriter(this, writer, key, expiredAt, metaHeaderSize, metaBodySize, maxSize, func() {
 			sharedWritingFileKeyLocker.Lock()
 			delete(sharedWritingFileKeyMap, key)
-			if len(sharedWritingFileKeyMap) == 0 {
-				maxOpenFiles.FinishAll()
-			}
 			sharedWritingFileKeyLocker.Unlock()
 		}), nil
 	}
diff --git a/internal/caches/storage_memory.go b/internal/caches/storage_memory.go
index 7fd381f..f432a9d 100644
--- a/internal/caches/storage_memory.go
+++ b/internal/caches/storage_memory.go
@@ -488,10 +488,8 @@ func (this *MemoryStorage) startFlush() {
 				if err == nil && loadStat != nil {
 					if loadStat.Load1 > 10 {
 						writeDelayMS = 100
-					} else if loadStat.Load1 > 3 {
+					} else if loadStat.Load1 > 5 {
 						writeDelayMS = 50
-					} else if loadStat.Load1 > 2 {
-						writeDelayMS = 10
 					} else {
 						writeDelayMS = 0
 					}
diff --git a/internal/caches/writer_file.go b/internal/caches/writer_file.go
index 2f915f5..514deee 100644
--- a/internal/caches/writer_file.go
+++ b/internal/caches/writer_file.go
@@ -3,6 +3,7 @@ package caches
 import (
 	"encoding/binary"
 	"errors"
+	fsutils "github.com/TeaOSLab/EdgeNode/internal/utils/fs"
 	"github.com/iwind/TeaGo/types"
 	"io"
 	"os"
@@ -42,7 +43,9 @@ func NewFileWriter(storage StorageInterface, rawWriter *os.File, key string, exp
 
 // WriteHeader 写入数据
 func (this *FileWriter) WriteHeader(data []byte) (n int, err error) {
+	fsutils.WriteBegin()
 	n, err = this.rawWriter.Write(data)
+	fsutils.WriteEnd()
 	this.headerSize += int64(n)
 	if err != nil {
 		_ = this.Discard()
@@ -72,7 +75,9 @@ func (this *FileWriter) WriteHeaderLength(headerLength int) error {
 
 // Write 写入数据
 func (this *FileWriter) Write(data []byte) (n int, err error) {
+	fsutils.WriteBegin()
 	n, err = this.rawWriter.Write(data)
+	fsutils.WriteEnd()
 	this.bodySize += int64(n)
 
 	if this.maxSize > 0 && this.bodySize > this.maxSize {
diff --git a/internal/caches/writer_partial_file.go b/internal/caches/writer_partial_file.go
index c718a0f..cf4b3fd 100644
--- a/internal/caches/writer_partial_file.go
+++ b/internal/caches/writer_partial_file.go
@@ -4,6 +4,7 @@ package caches
 
 import (
 	"encoding/binary"
+	fsutils "github.com/TeaOSLab/EdgeNode/internal/utils/fs"
 	"github.com/iwind/TeaGo/types"
 	"io"
 	"os"
@@ -53,7 +54,9 @@ func (this *PartialFileWriter) WriteHeader(data []byte) (n int, err error) {
 	if !this.isNew {
 		return
 	}
+	fsutils.WriteBegin()
 	n, err = this.rawWriter.Write(data)
+	fsutils.WriteEnd()
 	this.headerSize += int64(n)
 	if err != nil {
 		_ = this.Discard()
@@ -62,7 +65,9 @@ func (this *PartialFileWriter) WriteHeader(data []byte) (n int, err error) {
 }
 
 func (this *PartialFileWriter) AppendHeader(data []byte) error {
+	fsutils.WriteBegin()
 	_, err := this.rawWriter.Write(data)
+	fsutils.WriteEnd()
 	if err != nil {
 		_ = this.Discard()
 	} else {
@@ -99,7 +104,9 @@ func (this *PartialFileWriter) WriteHeaderLength(headerLength int) error {
 
 // Write 写入数据
 func (this *PartialFileWriter) Write(data []byte) (n int, err error) {
+	fsutils.WriteBegin()
 	n, err = this.rawWriter.Write(data)
+	fsutils.WriteEnd()
 	this.bodySize += int64(n)
 	if err != nil {
 		_ = this.Discard()
@@ -128,7 +135,9 @@ func (this *PartialFileWriter) WriteAt(offset int64, data []byte) error {
 		this.bodyOffset = SizeMeta + int64(keyLength) + this.headerSize
 	}
 
+	fsutils.WriteBegin()
 	_, err := this.rawWriter.WriteAt(data, this.bodyOffset+offset)
+	fsutils.WriteEnd()
 	if err != nil {
 		return err
 	}
diff --git a/internal/const/vars.go b/internal/const/vars.go
index 32b4fe3..d8f5023 100644
--- a/internal/const/vars.go
+++ b/internal/const/vars.go
@@ -22,8 +22,6 @@ var (
 
 	IsQuiting    = false // 是否正在退出
 	EnableDBStat = false // 是否开启本地数据库统计
-
-	DiskIsFast = false // 是否为高速硬盘
 )
 
 // 检查是否为主程序
diff --git a/internal/nodes/node.go b/internal/nodes/node.go
index 5808725..c23087a 100644
--- a/internal/nodes/node.go
+++ b/internal/nodes/node.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"errors"
-	"fmt"
 	"github.com/TeaOSLab/EdgeCommon/pkg/configutils"
 	iplib "github.com/TeaOSLab/EdgeCommon/pkg/iplibrary"
 	"github.com/TeaOSLab/EdgeCommon/pkg/nodeconfigs"
@@ -27,7 +26,6 @@ import (
 	"github.com/TeaOSLab/EdgeNode/internal/utils"
 	_ "github.com/TeaOSLab/EdgeNode/internal/utils/agents" // 引入Agent管理器
 	_ "github.com/TeaOSLab/EdgeNode/internal/utils/clock"  // 触发时钟更新
-	fsutils "github.com/TeaOSLab/EdgeNode/internal/utils/fs"
 	"github.com/TeaOSLab/EdgeNode/internal/utils/jsonutils"
 	"github.com/TeaOSLab/EdgeNode/internal/waf"
 	"github.com/andybalholm/brotli"
@@ -143,9 +141,6 @@ func (this *Node) Start() {
 	// 调整系统参数
 	this.checkSystem()
 
-	// 检查硬盘
-	this.checkDisk()
-
 	// 启动事件
 	events.Notify(events.EventStart)
 
@@ -1112,21 +1107,6 @@ func (this *Node) checkSystem() {
 	}
 }
 
-// 检查硬盘
-func (this *Node) checkDisk() {
-	speedMB, isFast, err := fsutils.CheckDiskIsFast()
-	if err != nil {
-		remotelogs.Error("NODE", "check disk speed failed: "+err.Error())
-		return
-	}
-	teaconst.DiskIsFast = isFast
-	if isFast {
-		remotelogs.Println("NODE", "disk is fast, writing test speed: "+fmt.Sprintf("%.2fMB/s", speedMB))
-	} else {
-		remotelogs.Println("NODE", "disk is slow, writing test speed: "+fmt.Sprintf("%.2fMB/s", speedMB))
-	}
-}
-
 // 检查API节点地址
 func (this *Node) changeAPINodeAddrs(apiNodeAddrs []*serverconfigs.NetworkAddressConfig) {
 	var addrs = []string{}
diff --git a/internal/utils/fs/disk.go b/internal/utils/fs/disk.go
index 2ac98b6..c063cef 100644
--- a/internal/utils/fs/disk.go
+++ b/internal/utils/fs/disk.go
@@ -65,5 +65,11 @@ func CheckDiskIsFast() (speedMB float64, isFast bool, err error) {
 		return
 	}
 	isFast = speedMB > 120
+
+	if speedMB > DiskSpeedMB {
+		DiskSpeedMB = speedMB
+		DiskIsFast = isFast
+	}
+
 	return
 }
diff --git a/internal/utils/fs/status.go b/internal/utils/fs/status.go
new file mode 100644
index 0000000..9d3302d
--- /dev/null
+++ b/internal/utils/fs/status.go
@@ -0,0 +1,60 @@
+// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package fsutils
+
+import (
+	teaconst "github.com/TeaOSLab/EdgeNode/internal/const"
+	"sync/atomic"
+	"time"
+)
+
+var (
+	DiskIsFast  bool
+	DiskSpeedMB float64
+)
+
+func init() {
+	if !teaconst.IsMain {
+		return
+	}
+
+	// test disk
+	go func() {
+		// initial check
+		_, _, _ = CheckDiskIsFast()
+
+		// check every one hour
+		var ticker = time.NewTicker(1 * time.Hour)
+		var count = 0
+		for range ticker.C {
+			_, _, err := CheckDiskIsFast()
+			if err == nil {
+				count++
+				if count > 24 {
+					return
+				}
+			}
+		}
+	}()
+}
+
+var countWrites int32 = 0
+
+const MaxWrites = 32
+const MaxFastWrites = 128
+
+func WriteReady() bool {
+	var count = atomic.LoadInt32(&countWrites)
+	if DiskIsFast {
+		return count < MaxFastWrites
+	}
+	return count <= MaxWrites
+}
+
+func WriteBegin() {
+	atomic.AddInt32(&countWrites, 1)
+}
+
+func WriteEnd() {
+	atomic.AddInt32(&countWrites, -1)
+}
diff --git a/internal/utils/fs/status_test.go b/internal/utils/fs/status_test.go
new file mode 100644
index 0000000..c322984
--- /dev/null
+++ b/internal/utils/fs/status_test.go
@@ -0,0 +1,31 @@
+// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package fsutils_test
+
+import (
+	fsutils "github.com/TeaOSLab/EdgeNode/internal/utils/fs"
+	"github.com/iwind/TeaGo/assert"
+	"testing"
+)
+
+func TestWrites(t *testing.T) {
+	var a = assert.NewAssertion(t)
+
+	for i := 0; i < fsutils.MaxWrites+1; i++ {
+		fsutils.WriteBegin()
+	}
+	a.IsFalse(fsutils.WriteReady())
+
+	fsutils.WriteEnd()
+	a.IsTrue(fsutils.WriteReady())
+}
+
+func BenchmarkWrites(b *testing.B) {
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			fsutils.WriteReady()
+			fsutils.WriteBegin()
+			fsutils.WriteEnd()
+		}
+	})
+}