6 files changed, 100 insertions, 1 deletions
diff --git a/internal/collector/collector.go b/internal/collector/collector.go
index 0107d61..5c99347 100644
--- a/internal/collector/collector.go
+++ b/internal/collector/collector.go
@@ -18,6 +18,7 @@ type StatsStore interface {
 	SetCPU(host, name string, line CPULine)
 	SetMem(host, key string, value int64)
 	SetNet(host, iface string, net NetLine, stamp float64)
+	SetDisk(host, device string, disk DiskLine, stamp float64)
 }
 
 // Run starts a collector for one host: runs the embedded remote script (local or over SSH)
@@ -134,6 +135,10 @@ func dispatchCollectorLine(mode, line, hostKey string, store StatsStore) {
 				store.SetNet(hostKey, net.Iface, net, float64(time.Now().UnixNano())/1e9)
 			}
 		}
+	case ModeDiskStats:
+		if d, err := ParseDiskLine(line); err == nil {
+			store.SetDisk(hostKey, d.Device, d, float64(time.Now().UnixNano())/1e9)
+		}
 	case ModeCPUStats:
 		if strings.HasPrefix(line, "cpu") {
 			if cu, err := ParseCPULine(line); err == nil {
diff --git a/internal/collector/parse.go b/internal/collector/parse.go
index 4f49456..034a50b 100644
--- a/internal/collector/parse.go
+++ b/internal/collector/parse.go
@@ -100,3 +100,33 @@ func ParseLoadAvg(line string) LoadAvg {
 	}
 	return l
 }
+
+// ParseDiskLine parses "device:rs=N;ws=N;rt=N;wt=N;io=N" from the M DISKSTATS section.
+func ParseDiskLine(line string) (DiskLine, error) {
+	parts := strings.SplitN(line, ":", 2)
+	if len(parts) != 2 {
+		return DiskLine{}, fmt.Errorf("disk line missing colon: %q", line)
+	}
+	d := DiskLine{Device: strings.TrimSpace(parts[0])}
+	for _, pair := range strings.Split(parts[1], ";") {
+		kv := strings.SplitN(pair, "=", 2)
+		if len(kv) != 2 {
+			continue
+		}
+		k := strings.TrimSpace(kv[0])
+		v, _ := strconv.ParseInt(strings.TrimSpace(kv[1]), 10, 64)
+		switch k {
+		case "rs":
+			d.SectorsRead = v
+		case "ws":
+			d.SectorsWrite = v
+		case "rt":
+			d.ReadTicks = v
+		case "wt":
+			d.WriteTicks = v
+		case "io":
+			d.IoTicks = v
+		}
+	}
+	return d, nil
+}
diff --git a/internal/collector/parse_test.go b/internal/collector/parse_test.go
index fe7a73c..8d569cd 100644
--- a/internal/collector/parse_test.go
+++ b/internal/collector/parse_test.go
@@ -115,3 +115,46 @@ func TestParseLoadAvg(t *testing.T) {
 		t.Errorf("ParseLoadAvg(1.0) = %+v", got2)
 	}
 }
+
+func TestParseDiskLine(t *testing.T) {
+	tests := []struct {
+		name         string
+		line         string
+		wantDevice   string
+		wantSR       int64
+		wantSW       int64
+		wantRT       int64
+		wantWT       int64
+		wantIO       int64
+		wantErr      bool
+	}{
+		{"full", "sda:rs=1000;ws=2000;rt=50;wt=100;io=120", "sda", 1000, 2000, 50, 100, 120, false},
+		{"nvme", "nvme0n1:rs=500;ws=300;rt=10;wt=20;io=30", "nvme0n1", 500, 300, 10, 20, 30, false},
+		{"zeros", "vda:rs=0;ws=0;rt=0;wt=0;io=0", "vda", 0, 0, 0, 0, 0, false},
+		{"large_counters", "sda:rs=9999999999;ws=8888888888;rt=100;wt=200;io=300", "sda", 9999999999, 8888888888, 100, 200, 300, false},
+		{"partial_fields", "sda:rs=100;ws=200", "sda", 100, 200, 0, 0, 0, false},
+		{"no_colon", "sda rs=100", "", 0, 0, 0, 0, 0, true},
+		{"empty", "", "", 0, 0, 0, 0, 0, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := ParseDiskLine(tt.line)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ParseDiskLine() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if tt.wantErr {
+				return
+			}
+			if got.Device != tt.wantDevice {
+				t.Errorf("Device = %q, want %q", got.Device, tt.wantDevice)
+			}
+			if got.SectorsRead != tt.wantSR || got.SectorsWrite != tt.wantSW {
+				t.Errorf("Sectors = read:%d write:%d, want read:%d write:%d", got.SectorsRead, got.SectorsWrite, tt.wantSR, tt.wantSW)
+			}
+			if got.ReadTicks != tt.wantRT || got.WriteTicks != tt.wantWT || got.IoTicks != tt.wantIO {
+				t.Errorf("Ticks = rt:%d wt:%d io:%d, want rt:%d wt:%d io:%d", got.ReadTicks, got.WriteTicks, got.IoTicks, tt.wantRT, tt.wantWT, tt.wantIO)
+			}
+		})
+	}
+}
diff --git a/internal/collector/protocol.go b/internal/collector/protocol.go
index 26e8a8d..92557e1 100644
--- a/internal/collector/protocol.go
+++ b/internal/collector/protocol.go
@@ -5,5 +5,6 @@ const (
 	ModeLoadAvg  = "M LOADAVG"
 	ModeMemStats = "M MEMSTATS"
 	ModeNetStats = "M NETSTATS"
-	ModeCPUStats = "M CPUSTATS"
+	ModeDiskStats = "M DISKSTATS"
+	ModeCPUStats  = "M CPUSTATS"
 )
diff --git a/internal/collector/scriptdata/loadbars-remote.sh b/internal/collector/scriptdata/loadbars-remote.sh
index 9037ad8..1bdb661 100644
--- a/internal/collector/scriptdata/loadbars-remote.sh
+++ b/internal/collector/scriptdata/loadbars-remote.sh
@@ -26,6 +26,16 @@ while true; do
     fi
   done < <(tail -n +3 /proc/net/dev 2>/dev/null)
 
+  # Disk: /proc/diskstats, one line per block device with cumulative counters
+  echo "M DISKSTATS"
+  while IFS= read -r line; do
+    set -- $line
+    # $1=major $2=minor $3=device $4=reads_completed $5=reads_merged
+    # $6=sectors_read $7=ms_reading $8=writes_completed $9=writes_merged
+    # $10=sectors_written $11=ms_writing $12=ios_in_progress $13=ms_io
+    [ -n "$3" ] && echo "$3:rs=${6:-0};ws=${10:-0};rt=${7:-0};wt=${11:-0};io=${13:-0}"
+  done < /proc/diskstats 2>/dev/null
+
   # CPU: /proc/stat, 20 times with INTERVAL sleep
   echo "M CPUSTATS"
   for _ in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20; do
diff --git a/internal/collector/types.go b/internal/collector/types.go
index 13bcb1f..6d1ecf0 100644
--- a/internal/collector/types.go
+++ b/internal/collector/types.go
@@ -34,3 +34,13 @@ type NetLine struct {
 type LoadAvg struct {
 	Load1, Load5, Load15 string
 }
+
+// DiskLine is one device from /proc/diskstats with cumulative counters.
+type DiskLine struct {
+	Device       string
+	SectorsRead  int64 // cumulative sectors read (each sector = 512 bytes)
+	SectorsWrite int64 // cumulative sectors written
+	ReadTicks    int64 // cumulative ms spent reading
+	WriteTicks   int64 // cumulative ms spent writing
+	IoTicks      int64 // cumulative ms the device had I/O in progress
+}