diff --git a/daemon_state_android.cc b/daemon_state_android.cc
index c9c09b8..3376e64 100644
--- a/daemon_state_android.cc
+++ b/daemon_state_android.cc
@@ -45,17 +45,17 @@
 
   // Initialize prefs.
   base::FilePath non_volatile_path;
-  // TODO(deymo): Fall back to in-memory prefs if there's no physical directory
-  // available.
   if (!hardware_->GetNonVolatileDirectory(&non_volatile_path)) {
-    LOG(ERROR) << "Failed to get a non-volatile directory.";
-    return false;
-  }
-  Prefs* prefs = new Prefs();
-  prefs_.reset(prefs);
-  if (!prefs->Init(non_volatile_path.Append(kPrefsSubDirectory))) {
-    LOG(ERROR) << "Failed to initialize preferences.";
-    return false;
+    prefs_.reset(new MemoryPrefs());
+    LOG(WARNING)
+        << "Could not get a non-volatile directory, fall back to memory prefs";
+  } else {
+    Prefs* prefs = new Prefs();
+    prefs_.reset(prefs);
+    if (!prefs->Init(non_volatile_path.Append(kPrefsSubDirectory))) {
+      LOG(ERROR) << "Failed to initialize preferences.";
+      return false;
+    }
   }
 
   // The CertificateChecker singleton is used by the update attempter.
diff --git a/payload_consumer/filesystem_verifier_action.cc b/payload_consumer/filesystem_verifier_action.cc
index f9e7f81..5b2b5f4 100644
--- a/payload_consumer/filesystem_verifier_action.cc
+++ b/payload_consumer/filesystem_verifier_action.cc
@@ -77,9 +77,16 @@
     return;
   if (code == ErrorCode::kSuccess && HasOutputPipe())
     SetOutputObject(install_plan_);
+  UpdateProgress(1.0);
   processor_->ActionComplete(this, code);
 }
 
+void FilesystemVerifierAction::UpdateProgress(double progress) {
+  if (delegate_ != nullptr) {
+    delegate_->OnVerifyProgressUpdate(progress);
+  }
+}
+
 void FilesystemVerifierAction::StartPartitionHashing() {
   if (partition_index_ == install_plan_.partitions.size()) {
     Cleanup(ErrorCode::kSuccess);
@@ -188,7 +195,6 @@
     Cleanup(ErrorCode::kError);
     return;
   }
-
   if (bytes_read == 0) {
     LOG(ERROR) << "Failed to read the remaining " << partition_size_ - offset_
                << " bytes from partition "
@@ -203,6 +209,13 @@
     return;
   }
 
+  // WE don't consider sizes of each partition. Every partition
+  // has the same length on progress bar.
+  // TODO(zhangkelvin) Take sizes of each partition into account
+
+  UpdateProgress(
+      (static_cast<double>(offset_) / partition_size_ + partition_index_) /
+      install_plan_.partitions.size());
   if (verifier_step_ == VerifierStep::kVerifyTargetHash &&
       install_plan_.write_verity) {
     if (!verity_writer_->Update(offset_, buffer_.data(), bytes_read)) {
diff --git a/payload_consumer/filesystem_verifier_action.h b/payload_consumer/filesystem_verifier_action.h
index 83d6668..6ef3d16 100644
--- a/payload_consumer/filesystem_verifier_action.h
+++ b/payload_consumer/filesystem_verifier_action.h
@@ -49,6 +49,12 @@
   kVerifySourceHash,
 };
 
+class FilesystemVerifyDelegate {
+ public:
+  virtual ~FilesystemVerifyDelegate() = default;
+  virtual void OnVerifyProgressUpdate(double progress) = 0;
+};
+
 class FilesystemVerifierAction : public InstallPlanAction {
  public:
   FilesystemVerifierAction()
@@ -58,6 +64,14 @@
   void PerformAction() override;
   void TerminateProcessing() override;
 
+  // Used for listening to progress updates
+  void set_delegate(FilesystemVerifyDelegate* delegate) {
+    this->delegate_ = delegate;
+  }
+  [[nodiscard]] FilesystemVerifyDelegate* get_delegate() const {
+    return this->delegate_;
+  }
+
   // Debugging/logging
   static std::string StaticType() { return "FilesystemVerifierAction"; }
   std::string Type() const override { return StaticType(); }
@@ -85,6 +99,9 @@
   // true if TerminateProcessing() was called.
   void Cleanup(ErrorCode code);
 
+  // Invoke delegate callback to report progress, if delegate is not null
+  void UpdateProgress(double progress);
+
   // The type of the partition that we are verifying.
   VerifierStep verifier_step_ = VerifierStep::kVerifyTargetHash;
 
@@ -119,6 +136,9 @@
   // The byte offset that we are reading in the current partition.
   uint64_t offset_{0};
 
+  // An observer that observes progress updates of this action.
+  FilesystemVerifyDelegate* delegate_{};
+
   DISALLOW_COPY_AND_ASSIGN(FilesystemVerifierAction);
 };
 
diff --git a/update_attempter_android.cc b/update_attempter_android.cc
index b7d119f..4d74379 100644
--- a/update_attempter_android.cc
+++ b/update_attempter_android.cc
@@ -576,9 +576,9 @@
     cleanup_previous_update_code_ = code;
     NotifyCleanupPreviousUpdateCallbacksAndClear();
   }
-  if (type == DownloadAction::StaticType()) {
-    download_progress_ = 0;
-  }
+  // download_progress_ is actually used by other actions, such as
+  // filesystem_verify_action. Therefore we always clear it.
+  download_progress_ = 0;
   if (type == PostinstallRunnerAction::StaticType()) {
     bool succeeded =
         code == ErrorCode::kSuccess || code == ErrorCode::kUpdatedButNotActive;
@@ -592,8 +592,9 @@
     SetStatusAndNotify(UpdateStatus::CLEANUP_PREVIOUS_UPDATE);
   }
   if (type == DownloadAction::StaticType()) {
-    SetStatusAndNotify(UpdateStatus::FINALIZING);
+    SetStatusAndNotify(UpdateStatus::VERIFYING);
   } else if (type == FilesystemVerifierAction::StaticType()) {
+    SetStatusAndNotify(UpdateStatus::FINALIZING);
     prefs_->SetBoolean(kPrefsVerityWritten, true);
   }
 }
@@ -644,6 +645,11 @@
   }
 }
 
+void UpdateAttempterAndroid::OnVerifyProgressUpdate(double progress) {
+  assert(status_ == UpdateStatus::VERIFYING);
+  ProgressUpdate(progress);
+}
+
 void UpdateAttempterAndroid::ScheduleProcessingStart() {
   LOG(INFO) << "Scheduling an action processor start.";
   brillo::MessageLoop::current()->PostTask(
@@ -734,6 +740,7 @@
       std::make_unique<FilesystemVerifierAction>();
   auto postinstall_runner_action =
       std::make_unique<PostinstallRunnerAction>(boot_control_, hardware_);
+  filesystem_verifier_action->set_delegate(this);
   postinstall_runner_action->set_delegate(this);
 
   // Bond them together. We have to use the leaf-types when calling
diff --git a/update_attempter_android.h b/update_attempter_android.h
index f8c78de..55003a0 100644
--- a/update_attempter_android.h
+++ b/update_attempter_android.h
@@ -37,6 +37,7 @@
 #include "update_engine/metrics_utils.h"
 #include "update_engine/network_selector_interface.h"
 #include "update_engine/payload_consumer/download_action.h"
+#include "update_engine/payload_consumer/filesystem_verifier_action.h"
 #include "update_engine/payload_consumer/postinstall_runner_action.h"
 #include "update_engine/service_delegate_android_interface.h"
 #include "update_engine/service_observer_interface.h"
@@ -47,6 +48,7 @@
     : public ServiceDelegateAndroidInterface,
       public ActionProcessorDelegate,
       public DownloadActionDelegate,
+      public FilesystemVerifyDelegate,
       public PostinstallRunnerAction::DelegateInterface,
       public CleanupPreviousUpdateActionDelegateInterface {
  public:
@@ -101,6 +103,9 @@
   bool ShouldCancel(ErrorCode* cancel_reason) override;
   void DownloadComplete() override;
 
+  // FilesystemVerifyDelegate overrides
+  void OnVerifyProgressUpdate(double progress) override;
+
   // PostinstallRunnerAction::DelegateInterface
   void ProgressUpdate(double progress) override;