diff --git a/test/os.go b/test/os.go
index 96561d3..8458ce3 100644
--- a/test/os.go
+++ b/test/os.go
@@ -7,7 +7,7 @@ import (
 
 func main() {
 	funcs := []func(){
-		a, b, c, d, e,
+		a, b, c, d, e, f,
 	}
 	for i := 0; i < 1000; i++ {
 		fmt.Printf("------ %d -------\n", i)
diff --git a/test/os_darwin.go b/test/os_darwin.go
index 724c892..eaba45a 100644
--- a/test/os_darwin.go
+++ b/test/os_darwin.go
@@ -10,7 +10,6 @@ import (
 
 	"fmt"
 	"os"
-	"time"
 	"amuz.es/src/infra/goutils/misc"
 )
 
@@ -92,3 +91,7 @@ func e() {
 	fmt.Printf("cpu total: %d\n", ct.Total)
 	fmt.Printf("cpu user: %d\n", ct.User)
 }
+
+func f() {
+	fmt.Fprintf(os.Stderr, "%s\n", "not supported")
+}
diff --git a/test/os_linux.go b/test/os_linux.go
index 95c714a..52c482b 100644
--- a/test/os_linux.go
+++ b/test/os_linux.go
@@ -6,6 +6,7 @@ import (
 	"github.com/mackerelio/go-osstat/network"
 	"github.com/mackerelio/go-osstat/uptime"
 	"github.com/mackerelio/go-osstat/cpu"
+	"github.com/mackerelio/go-osstat/disk"
 	"github.com/hako/durafmt"
 
 	"fmt"
@@ -104,3 +105,15 @@ func e() {
 	fmt.Printf("cpu steal: %d\n", ct.Steal)
 	fmt.Printf("cpu total: %d\n", ct.Total)
 }
+func f() {
+	disks, err := disk.Get()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%s\n", err)
+		return
+	}
+	for _, dsk := range disks {
+		fmt.Println("disk name: ", dsk.Name)
+		fmt.Println("disk read: ", misc.FileSizeIEC(dsk.ReadsCompleted))
+		fmt.Println("disk written: ", misc.FileSizeIEC(dsk.WritesCompleted))
+	}
+}
diff --git a/vendor/github.com/mackerelio/go-osstat/disk/disk_linux.go b/vendor/github.com/mackerelio/go-osstat/disk/disk_linux.go
new file mode 100644
index 0000000..b9b4a3a
--- /dev/null
+++ b/vendor/github.com/mackerelio/go-osstat/disk/disk_linux.go
@@ -0,0 +1,58 @@
+// +build linux
+
+package disk
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// Get disk I/O statistics
+func Get() ([]Stats, error) {
+	// Reference: Documentation/iostats.txt in the source of Linux
+	file, err := os.Open("/proc/diskstats")
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	return collectDiskStats(file)
+}
+
+// Stats represents disk I/O statistics for linux
+type Stats struct {
+	Name                            string
+	ReadsCompleted, WritesCompleted uint64
+}
+
+func collectDiskStats(out io.Reader) ([]Stats, error) {
+	scanner := bufio.NewScanner(out)
+	var diskStats []Stats
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 14 {
+			continue
+		}
+		name := fields[2]
+		readsCompleted, err := strconv.ParseUint(fields[3], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse reads completed of %s", name)
+		}
+		writesCompleted, err := strconv.ParseUint(fields[7], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse writes completed of %s", name)
+		}
+		diskStats = append(diskStats, Stats{
+			Name:            name,
+			ReadsCompleted:  readsCompleted,
+			WritesCompleted: writesCompleted,
+		})
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("scan error for /proc/diskstats: %s", err)
+	}
+	return diskStats, nil
+}
diff --git a/vendor/github.com/mackerelio/go-osstat/disk/disk_linux_test.go b/vendor/github.com/mackerelio/go-osstat/disk/disk_linux_test.go
new file mode 100644
index 0000000..9b70fb1
--- /dev/null
+++ b/vendor/github.com/mackerelio/go-osstat/disk/disk_linux_test.go
@@ -0,0 +1,44 @@
+// +build linux
+
+package disk
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestGetDisk(t *testing.T) {
+	disks, err := Get()
+	if err != nil {
+		t.Fatalf("error should be nil but got: %v", err)
+	}
+	t.Logf("disks value: %+v", disks)
+}
+
+func TestCollectDiskStats(t *testing.T) {
+	got, err := collectDiskStats(strings.NewReader(
+		` 202       1 xvda1 750193 3037 28116978 368712 16600606 7233846 424712632 23987908 0 2355636 24345740
+ 202       2 xvda2 1641 9310 87552 1252 6365 3717 80664 24192 0 15040 25428
+   7       0 loop0 0 0 0 0 0 0 0 0 0 0 0
+   7       1 loop1 0 0 0 0 0 0 0 0 0 0 0
+ 253       0 dm-0 46095806 0 549095028 2243928 7192424 0 305024576 12521088 0 2728444 14782668
+ 253     628 dm-628 3198 0 75410 1360 30802835 0 3942653176 1334317408 0 70948 1358596768
+ 253       2 dm-2 2022 0 42250 488 30822403 0 3942809696 1364721232 0 93348 1382989868
+`))
+	if err != nil {
+		t.Fatalf("error should be nil but got: %v", err)
+	}
+	expected := []Stats{
+		{"xvda1", 750193, 16600606},
+		{"xvda2", 1641, 6365},
+		{"loop0", 0, 0},
+		{"loop1", 0, 0},
+		{"dm-0", 46095806, 7192424},
+		{"dm-628", 3198, 30802835},
+		{"dm-2", 2022, 30822403},
+	}
+	if !reflect.DeepEqual(got, expected) {
+		t.Errorf("invalid disk value: %+v (expected: %+v)", got, expected)
+	}
+}
diff --git a/vendor/vgo.list b/vendor/vgo.list
index 09a1137..c58d494 100644
--- a/vendor/vgo.list
+++ b/vendor/vgo.list
@@ -42,6 +42,7 @@ github.com/lestrrat-go/file-rotatelogs/internal/option
 github.com/lestrrat-go/strftime
 # github.com/mackerelio/go-osstat v0.0.0-20180312130411-192e3c5eacaf
 github.com/mackerelio/go-osstat/cpu
+github.com/mackerelio/go-osstat/disk
 github.com/mackerelio/go-osstat/loadavg
 github.com/mackerelio/go-osstat/memory
 github.com/mackerelio/go-osstat/network