@@ -440,9 +440,7 @@ func (clnt *client) AddProcess(ctx context.Context, containerID, processFriendly

 		return -1, err

 	}

-	defer func() {

-		container.debugGCS()

-	}()

+	defer container.debugGCS()

 	// Note we always tell HCS to

 	// create stdout as it's required regardless of '-i' or '-t' options, so that

@@ -59,9 +59,7 @@ func (ctr *container) start(attachStdio StdioCallback) error {

 		return err

 	}

-	defer func() {

-		ctr.debugGCS()

-	}()

+	defer ctr.debugGCS()

 	// Note we always tell HCS to

 	// create stdout as it's required regardless of '-i' or '-t' options, so that

@@ -24,7 +24,7 @@ func (s *LCOWOption) Apply(interface{}) error {

 	return nil

 }

-// DebugGCS is a dirty hack for debugging for Linux Utility VMs. It simply

+// debugGCS is a dirty hack for debugging for Linux Utility VMs. It simply

 // runs a bunch of commands inside the UVM, but seriously aides in advanced debugging.

 func (c *container) debugGCS() {

 	if c == nil || c.isWindows || c.hcsContainer == nil {

@@ -8,7 +8,7 @@ github.com/docker/libtrust 9cbd2a1374f46905c68a4eb3694a130610adc62a

 github.com/go-check/check 4ed411733c5785b40214c70bce814c3a3a689609 https://github.com/cpuguy83/check.git

 github.com/gorilla/context v1.1

 github.com/gorilla/mux v1.1

-github.com/Microsoft/opengcs v0.3.3

+github.com/Microsoft/opengcs v0.3.4

 github.com/kr/pty 5cf931ef8f

 github.com/mattn/go-shellwords v1.0.3

 github.com/sirupsen/logrus v1.0.1

@@ -57,6 +57,8 @@ func (config *Config) CreateExt4Vhdx(destFile string, sizeGB uint32, cacheFile s

 		return fmt.Errorf("failed to create VHDx %s: %s", destFile, err)

 	}

+	defer config.DebugGCS()

+

 	// Attach it to the utility VM, but don't mount it (as there's no filesystem on it)

 	if err := config.HotAddVhd(destFile, "", false, false); err != nil {

 		return fmt.Errorf("opengcs: CreateExt4Vhdx: failed to hot-add %s to utility VM: %s", cacheFile, err)

@@ -20,6 +20,8 @@ func (config *Config) HotAddVhd(hostPath string, containerPath string, readOnly

 		return fmt.Errorf("cannot hot-add VHD as no utility VM is in configuration")

 	}

+	defer config.DebugGCS()

+

 	modification := &hcsshim.ResourceModificationRequestResponse{

 		Resource: "MappedVirtualDisk",

 		Data: hcsshim.MappedVirtualDisk{

@@ -18,6 +18,8 @@ func (config *Config) HotRemoveVhd(hostPath string) error {

 		return fmt.Errorf("cannot hot-add VHD as no utility VM is in configuration")

 	}

+	defer config.DebugGCS()

+

 	modification := &hcsshim.ResourceModificationRequestResponse{

 		Resource: "MappedVirtualDisk",

 		Data: hcsshim.MappedVirtualDisk{

@@ -3,8 +3,12 @@

 package client

 import (

+	"bytes"

 	"fmt"

 	"io"

+	"os"

+	"strings"

+	"time"

 	"github.com/Microsoft/hcsshim"

 	"github.com/sirupsen/logrus"

@@ -110,3 +114,44 @@ func (config *Config) RunProcess(commandLine string, stdin io.Reader, stdout io.

 	logrus.Debugf("opengcs: runProcess success: %s", commandLine)

 	return process.Process, nil

 }

+

+func debugCommand(s string) string {

+	return fmt.Sprintf(`echo -e 'DEBUG COMMAND: %s\\n--------------\\n';%s;echo -e '\\n\\n';`, s, s)

+}

+

+// DebugGCS extracts logs from the GCS. It's a useful hack for debugging,

+// but not necessarily optimal, but all that is available to us in RS3.

+func (config *Config) DebugGCS() {

+	if logrus.GetLevel() < logrus.DebugLevel || len(os.Getenv("OPENGCS_DEBUG_ENABLE")) == 0 {

+		return

+	}

+

+	var out bytes.Buffer

+	cmd := os.Getenv("OPENGCS_DEBUG_COMMAND")

+	if cmd == "" {

+		cmd = `sh -c "`

+		cmd += debugCommand("ls -l /tmp")

+		cmd += debugCommand("cat /tmp/gcs.log")

+		cmd += debugCommand("ls -l /tmp/gcs")

+		cmd += debugCommand("ls -l /tmp/gcs/*")

+		cmd += debugCommand("cat /tmp/gcs/*/config.json")

+		cmd += debugCommand("ls -lR /var/run/gcsrunc")

+		cmd += debugCommand("cat /var/run/gcsrunc/log.log")

+		cmd += debugCommand("ps -ef")

+		cmd += `"`

+	}

+	proc, err := config.RunProcess(cmd, nil, &out, nil)

+	defer func() {

+		if proc != nil {

+			proc.Kill()

+			proc.Close()

+		}

+	}()

+	if err != nil {

+		logrus.Debugln("benign failure getting gcs logs: ", err)

+	}

+	if proc != nil {

+		proc.WaitTimeout(time.Duration(int(time.Second) * 30))

+	}

+	logrus.Debugf("GCS Debugging:\n%s\n\nEnd GCS Debugging\n", strings.TrimSpace(out.String()))

+}

@@ -17,6 +17,8 @@ func (config *Config) TarToVhd(targetVHDFile string, reader io.Reader) (int64, e

 		return 0, fmt.Errorf("cannot Tar2Vhd as no utility VM is in configuration")

 	}

+	defer config.DebugGCS()

+

 	process, err := config.createUtilsProcess("tar2vhd")

 	if err != nil {

 		return 0, fmt.Errorf("failed to start tar2vhd for %s: %s", targetVHDFile, err)

@@ -20,6 +20,8 @@ func (config *Config) VhdToTar(vhdFile string, uvmMountPath string, isSandbox bo

 		return nil, fmt.Errorf("cannot VhdToTar as no utility VM is in configuration")

 	}

+	defer config.DebugGCS()

+

 	vhdHandle, err := os.Open(vhdFile)

 	if err != nil {

 		return nil, fmt.Errorf("opengcs: VhdToTar: failed to open %s: %s", vhdFile, err)