diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0716b33..780f961 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,18 @@
 # Changelog
 
+## v1.7.0 (12.09.2018)
+
+### Enhancements
+
+* New `unmount-volume` command checks if Mesos agent had problems unmounting local persistent volumes.
+* New `FindFirstLine` function helps to search in logs.
+
+### Bug fixes
+
+* Bun launches a random subcommand instead of the specified one.
+
+Kudos to Jan and Marvin for sponsoring this release with their company.
+
 ## v1.6.0 (10.09.2018)
 
 ### Enhancements
diff --git a/bun/cmd/import.go b/bun/cmd/import.go
index 2ba5513..754b9c7 100644
--- a/bun/cmd/import.go
+++ b/bun/cmd/import.go
@@ -4,8 +4,10 @@ import (
 	_ "github.com/adyatlov/bun/check/dcosversion"
 	_ "github.com/adyatlov/bun/check/health"
 	_ "github.com/adyatlov/bun/check/mesos/actormailboxes"
+	_ "github.com/adyatlov/bun/check/mesos/unmountvolume"
 	_ "github.com/adyatlov/bun/check/nodecount"
 	_ "github.com/adyatlov/bun/file/dcosversionfile"
 	_ "github.com/adyatlov/bun/file/healthfile"
 	_ "github.com/adyatlov/bun/file/mesos/actormailboxesfile"
+	_ "github.com/adyatlov/bun/file/mesos/agentlog"
 )
diff --git a/bun/cmd/root.go b/bun/cmd/root.go
index 6c5cd3e..fddb6a0 100644
--- a/bun/cmd/root.go
+++ b/bun/cmd/root.go
@@ -36,21 +36,22 @@ func init() {
 	rootCmd.PersistentFlags().BoolVarP(&printLong, "long", "l", false,
 		"print details")
 	// Adding registered checks as commands.
-	for _, check := range bun.Checks() {
+	for _, c := range bun.Checks() {
 		run := func(cmd *cobra.Command, args []string) {
+			check := bun.GetCheck(cmd.Use)
 			check.Run(*bundle)
 			printReport(check)
 			return
 		}
 		var cmd = &cobra.Command{
-			Use:    check.Name,
-			Short:  check.Description,
-			Long:   check.Description,
+			Use:    c.Name,
+			Short:  c.Description,
+			Long:   c.Description,
 			PreRun: preRun,
 			Run:    run,
 		}
 		rootCmd.AddCommand(cmd)
-		rootCmd.ValidArgs = append(rootCmd.ValidArgs, check.Name)
+		rootCmd.ValidArgs = append(rootCmd.ValidArgs, cmd.Use)
 		rootCmd.PreRun = preRun
 	}
 }
diff --git a/check/mesos/unmountvolume/unmount_volume.go b/check/mesos/unmountvolume/unmount_volume.go
new file mode 100644
index 0000000..db02be3
--- /dev/null
+++ b/check/mesos/unmountvolume/unmount_volume.go
@@ -0,0 +1,30 @@
+package unmountvolume
+
+import (
+	"fmt"
+
+	"github.com/adyatlov/bun"
+)
+
+func init() {
+	builder := bun.CheckBuilder{
+		Name:               "unmount-volume",
+		Description:        "Checks if Mesos agents had problems unmounting local persistent volumes",
+		ForEachAgent:       check,
+		ForEachPublicAgent: check,
+	}
+	builder.BuildAndRegister()
+}
+
+func check(host bun.Host) (ok bool, details interface{}, err error) {
+	line, n, err := host.FindFirstLine("mesos-agent-log", "Failed to destroy nested containers")
+	if err != nil {
+		return
+	}
+	if n != 0 {
+		details = fmt.Sprintf("%v: %v", n, line)
+		return
+	}
+	ok = true
+	return
+}
diff --git a/file/mesos/agentlog/agent_log.go b/file/mesos/agentlog/agent_log.go
new file mode 100644
index 0000000..6531aa2
--- /dev/null
+++ b/file/mesos/agentlog/agent_log.go
@@ -0,0 +1,17 @@
+package agentlog
+
+import "github.com/adyatlov/bun"
+
+func init() {
+	f := bun.FileType{
+		Name:        "mesos-agent-log",
+		ContentType: bun.Journal,
+		Paths: []string{
+			"dcos-mesos-slave.service",
+			"dcos-mesos-slave-public.service",
+		},
+		Description: "Mesos agent jounrald log",
+		HostTypes:   map[bun.HostType]struct{}{bun.Agent: {}, bun.PublicAgent: {}},
+	}
+	bun.RegisterFileType(f)
+}
diff --git a/file_owner.go b/file_owner.go
index 9adb399..863312c 100644
--- a/file_owner.go
+++ b/file_owner.go
@@ -1,6 +1,7 @@
 package bun
 
 import (
+	"bufio"
 	"compress/gzip"
 	"encoding/json"
 	"errors"
@@ -17,6 +18,21 @@ type fileOwner struct {
 	Path string
 }
 
+type bulkCloser []io.Closer
+
+func (bc bulkCloser) Close() error {
+	e := []string{}
+	for _, c := range bc {
+		if err := c.Close(); err != nil {
+			e = append(e, err.Error())
+		}
+	}
+	if len(e) > 0 {
+		return errors.New(strings.Join(e, "\n"))
+	}
+	return nil
+}
+
 // OpenFile opens the files of the typeName file type.
 // If the file is not found, it tries to open it from a correspondent .gzip archive.
 // If the .gzip archive is not found as well then returns an error.
@@ -45,6 +61,7 @@ func (fo fileOwner) OpenFile(typeName string) (File, error) {
 			notFound = append(notFound, filePath)
 			continue // not found
 		}
+		// found
 		r, err := gzip.NewReader(file)
 		if err != nil {
 			return nil, err // error
@@ -52,7 +69,7 @@ func (fo fileOwner) OpenFile(typeName string) (File, error) {
 		return struct {
 			io.Reader
 			io.Closer
-		}{io.Reader(r), bulkCloser{r, file}}, nil // found
+		}{io.Reader(r), bulkCloser{r, file}}, nil
 	}
 	return nil, fmt.Errorf("none of the following files are found:\n%v",
 		strings.Join(notFound, "\n"))
@@ -78,17 +95,27 @@ func (fo fileOwner) ReadJSON(typeName string, v interface{}) error {
 	return json.Unmarshal(data, v)
 }
 
-type bulkCloser []io.Closer
+func (fo fileOwner) FindFirstLine(typeName string, substr string) (l string, n int, err error) {
+	file, err := fo.OpenFile(typeName)
+	if err != nil {
+		return
+	}
+	return findFirstLine(file, substr)
+}
 
-func (bc bulkCloser) Close() error {
-	e := []string{}
-	for _, c := range bc {
-		if err := c.Close(); err != nil {
-			e = append(e, err.Error())
+func findFirstLine(r io.Reader, substr string) (l string, n int, err error) {
+	scanner := bufio.NewScanner(r)
+	for i := 1; scanner.Scan(); i++ {
+		line := scanner.Text()
+		if strings.Contains(line, substr) {
+			l = line
+			n = i
+			return
 		}
 	}
-	if len(e) > 0 {
-		return errors.New(strings.Join(e, "\n"))
+	if err = scanner.Err(); err != nil {
+		return
 	}
-	return nil
+	// Not found
+	return
 }
diff --git a/file_owner_test.go b/file_owner_test.go
new file mode 100644
index 0000000..33a3db8
--- /dev/null
+++ b/file_owner_test.go
@@ -0,0 +1,28 @@
+package bun
+
+import (
+	"strings"
+	"testing"
+)
+
+const str = `“Would you tell me, please, which way I ought to go from here?”
+“That depends a good deal on where you want to get to,” said the Cat.
+“I don’t much care where-–” said Alice.
+“Then it doesn’t matter which way you go,” said the Cat.
+“-–so long as I get SOMEWHERE,” Alice added as an explanation.
+“Oh, you’re sure to do that,” said the Cat, “if you only walk long enough.”`
+
+func TestFindFirstLine(t *testing.T) {
+	r := strings.NewReader(str)
+	line, n, err := findFirstLine(r, "SOMEWHERE")
+	const expected = `“-–so long as I get SOMEWHERE,” Alice added as an explanation.`
+	if line != expected {
+		t.Errorf("Epected line = \"%v\", observed \"%v\"", expected, line)
+	}
+	if n != 5 {
+		t.Errorf("Expected n = 5, observed n = %v", n)
+	}
+	if err != nil {
+		t.Errorf("Expected err = nil, observed err = %v", err)
+	}
+}