@@ -6,6 +6,7 @@ import (

 	"github.com/dotcloud/docker/auth"

 	"io"

 	"io/ioutil"

+	"log"

 	"os"

 	"os/exec"

 	"path"

@@ -23,6 +24,7 @@ type Runtime struct {

 	repositories   *TagStore

 	authConfig     *auth.AuthConfig

 	idIndex        *TruncIndex

+	kernelVersion  *KernelVersionInfo

 }

 var sysInitPath string

@@ -282,7 +284,22 @@ func (runtime *Runtime) restore() error {

 // FIXME: harmonize with NewGraph()

 func NewRuntime() (*Runtime, error) {

-	return NewRuntimeFromDirectory("/var/lib/docker")

+	runtime, err := NewRuntimeFromDirectory("/var/lib/docker")

+	if err != nil {

+		return nil, err

+	}

+

+	k, err := GetKernelVersion()

+	if err != nil {

+		return nil, err

+	}

+	runtime.kernelVersion = k

+

+	if CompareKernelVersion(k, &KernelVersionInfo{Kernel: 3, Major: 8, Minor: 0}) < 0 {

+		log.Printf("WARNING: You are running linux kernel version %s, which might be unstable running docker. Please upgrade your kernel to 3.8.0.", k.String())

+	}

+

+	return runtime, nil

 }

 func NewRuntimeFromDirectory(root string) (*Runtime, error) {

@@ -13,8 +13,10 @@ import (

 	"os/exec"

 	"path/filepath"

 	"runtime"

+	"strconv"

 	"strings"

 	"sync"

+	"syscall"

 	"time"

 )

@@ -384,3 +386,95 @@ func CopyEscapable(dst io.Writer, src io.ReadCloser) (written int64, err error)

 	}

 	return written, err

 }

+

+type KernelVersionInfo struct {

+	Kernel   int

+	Major    int

+	Minor    int

+	Specific int

+}

+

+func GetKernelVersion() (*KernelVersionInfo, error) {

+	var uts syscall.Utsname

+

+	if err := syscall.Uname(&uts); err != nil {

+		return nil, err

+	}

+

+	release := make([]byte, len(uts.Release))

+

+	i := 0

+	for _, c := range uts.Release {

+		release[i] = byte(c)

+		i++

+	}

+

+	tmp := strings.SplitN(string(release), "-", 2)

+	if len(tmp) != 2 {

+		return nil, fmt.Errorf("Unrecognized kernel version")

+	}

+	tmp2 := strings.SplitN(tmp[0], ".", 3)

+	if len(tmp2) != 3 {

+		return nil, fmt.Errorf("Unrecognized kernel version")

+	}

+

+	kernel, err := strconv.Atoi(tmp2[0])

+	if err != nil {

+		return nil, err

+	}

+

+	major, err := strconv.Atoi(tmp2[1])

+	if err != nil {

+		return nil, err

+	}

+

+	minor, err := strconv.Atoi(tmp2[2])

+	if err != nil {

+		return nil, err

+	}

+

+	specific, err := strconv.Atoi(strings.Split(tmp[1], "-")[0])

+	if err != nil {

+		return nil, err

+	}

+

+	return &KernelVersionInfo{

+		Kernel:   kernel,

+		Major:    major,

+		Minor:    minor,

+		Specific: specific,

+	}, nil

+}

+

+func (k *KernelVersionInfo) String() string {

+	return fmt.Sprintf("%d.%d.%d-%d", k.Kernel, k.Major, k.Minor, k.Specific)

+}

+

+// Compare two KernelVersionInfo struct.

+// Returns -1 if a < b, = if a == b, 1 it a > b

+func CompareKernelVersion(a, b *KernelVersionInfo) int {

+	if a.Kernel < b.Kernel {

+		return -1

+	} else if a.Kernel > b.Kernel {

+		return 1

+	}

+

+	if a.Major < b.Major {

+		return -1

+	} else if a.Major > b.Major {

+		return 1

+	}

+

+	if a.Minor < b.Minor {

+		return -1

+	} else if a.Minor > b.Minor {

+		return 1

+	}

+

+	if a.Specific < b.Specific {

+		return -1

+	} else if a.Specific > b.Specific {

+		return 1

+	}

+	return 0

+}