diff --git a/include/wfslib/blocks_device.h b/include/wfslib/blocks_device.h
index aedcb6b..4c08203 100644
--- a/include/wfslib/blocks_device.h
+++ b/include/wfslib/blocks_device.h
@@ -22,16 +22,19 @@ class BlocksDevice {
   BlocksDevice(const std::shared_ptr<Device>& device, const std::span<std::byte>& key);
 
   virtual void WriteBlock(uint32_t block_number,
+                          uint32_t size_in_blocks,
                           const std::span<std::byte>& data,
                           const std::span<std::byte>& hash,
                           uint32_t iv,
-                          bool encrypt);
+                          bool encrypt,
+                          bool recalculate_hash);
   virtual bool ReadBlock(uint32_t block_number,
+                         uint32_t size_in_blocks,
                          const std::span<std::byte>& data,
                          const std::span<const std::byte>& hash,
                          uint32_t iv,
                          bool encrypt,
-                         bool check_hash) const;
+                         bool check_hash);
 
   const Device* device() const { return device_.get(); }
 
diff --git a/include/wfslib/file_device.h b/include/wfslib/file_device.h
index 8ecd377..8b9180a 100644
--- a/include/wfslib/file_device.h
+++ b/include/wfslib/file_device.h
@@ -16,7 +16,11 @@ class Wfs;
 
 class FileDevice : public Device {
  public:
-  FileDevice(const std::string& path, uint32_t log2_sector_size = 9 /* 512 */, bool read_only = true);
+  FileDevice(const std::string& path,
+             uint32_t log2_sector_size = 9 /* 512 */,
+             uint32_t sectors_count = 0,
+             bool read_only = true,
+             bool create = false);
   void ReadSectors(const std::span<std::byte>& data, uint32_t sector_address, uint32_t sectors_count) override;
   void WriteSectors(const std::span<std::byte>& data, uint32_t sector_address, uint32_t sectors_count) override;
   uint32_t SectorsCount() const override { return sectors_count_; }
diff --git a/include/wfslib/wfs.h b/include/wfslib/wfs.h
index ff91dcb..c1f538b 100644
--- a/include/wfslib/wfs.h
+++ b/include/wfslib/wfs.h
@@ -19,10 +19,12 @@ class Area;
 class WfsItem;
 class File;
 class Directory;
+class BlocksDevice;
 
 class Wfs {
  public:
   Wfs(const std::shared_ptr<Device>& device, const std::span<std::byte>& key);
+  Wfs(const std::shared_ptr<BlocksDevice>& device);
   ~Wfs();
 
   const std::shared_ptr<BlocksDevice>& GetDevice() { return device_; }
diff --git a/include/wfslib/wfs_item.h b/include/wfslib/wfs_item.h
index bbd67a2..11f5ebe 100644
--- a/include/wfslib/wfs_item.h
+++ b/include/wfslib/wfs_item.h
@@ -30,6 +30,7 @@ class WfsItem {
   virtual bool IsDirectory() const;
   virtual bool IsFile() const;
   virtual bool IsLink() const;
+  virtual bool IsQuota() const;
 
  protected:
   AttributesBlock& attributes_data() { return attributes_; }
diff --git a/src/area.cpp b/src/area.cpp
index 9c74805..31ffd9c 100644
--- a/src/area.cpp
+++ b/src/area.cpp
@@ -16,7 +16,6 @@
 #include "utils.h"
 #include "wfs.h"
 
-
 Area::Area(const std::shared_ptr<BlocksDevice>& device,
            const std::shared_ptr<Area>& root_area,
            const std::shared_ptr<MetadataBlock>& block,
@@ -54,6 +53,14 @@ std::expected<std::shared_ptr<Directory>, WfsError> Area::GetRootDirectory() {
                       root_directory_attributes_);
 }
 
+std::expected<std::shared_ptr<Directory>, WfsError> Area::GetShadowDirectory1() {
+  return GetDirectory(as_const(this)->header()->shadow_directory_block_number_1.value(), ".shadow_dir_1", {});
+}
+
+std::expected<std::shared_ptr<Directory>, WfsError> Area::GetShadowDirectory2() {
+  return GetDirectory(as_const(this)->header()->shadow_directory_block_number_2.value(), ".shadow_dir_1", {});
+}
+
 std::expected<std::shared_ptr<Area>, WfsError> Area::GetArea(uint32_t block_number,
                                                              const std::string& root_directory_name,
                                                              const AttributesBlock& root_directory_attributes,
diff --git a/src/area.h b/src/area.h
index af13f06..7d0caa9 100644
--- a/src/area.h
+++ b/src/area.h
@@ -38,6 +38,9 @@ class Area : public std::enable_shared_from_this<Area> {
 
   std::expected<std::shared_ptr<Directory>, WfsError> GetRootDirectory();
 
+  std::expected<std::shared_ptr<Directory>, WfsError> GetShadowDirectory1();
+  std::expected<std::shared_ptr<Directory>, WfsError> GetShadowDirectory2();
+
   std::expected<std::shared_ptr<Directory>, WfsError> GetDirectory(uint32_t block_number,
                                                                    const std::string& name,
                                                                    const AttributesBlock& attributes);
diff --git a/src/block.cpp b/src/block.cpp
index db1a24c..5d042f9 100644
--- a/src/block.cpp
+++ b/src/block.cpp
@@ -43,13 +43,15 @@ void Block::Resize(uint32_t data_size) {
 }
 
 bool Block::Fetch(bool check_hash) {
-  return device_->ReadBlock(block_number_, data_, as_const(this)->Hash(), iv_, encrypted_, check_hash);
+  return device_->ReadBlock(block_number_, 1 << (size_category_ - BlockSize::Basic), data_, as_const(this)->Hash(), iv_,
+                            encrypted_, check_hash);
 }
 
 void Block::Flush() {
   if (!dirty_)
     return;
-  device_->WriteBlock(block_number_, data_, Hash(), iv_, encrypted_);
+  device_->WriteBlock(block_number_, 1 << (size_category_ - BlockSize::Basic), data_, Hash(), iv_, encrypted_,
+                      /*recalculate_hash=*/true);
   dirty_ = false;
 }
 
diff --git a/src/blocks_device.cpp b/src/blocks_device.cpp
index 490c30b..3c26981 100644
--- a/src/blocks_device.cpp
+++ b/src/blocks_device.cpp
@@ -16,20 +16,24 @@ BlocksDevice::BlocksDevice(const std::shared_ptr<Device>& device, const std::spa
     : device_(device), device_encryption_(std::make_unique<DeviceEncryption>(device, key)) {}
 
 void BlocksDevice::WriteBlock(uint32_t block_number,
+                              uint32_t /*size_in_blocks*/,
                               const std::span<std::byte>& data,
                               const std::span<std::byte>& hash,
                               uint32_t iv,
-                              bool encrypt) {
-  device_encryption_->CalculateHash(data, hash);
+                              bool encrypt,
+                              bool recalculate_hash) {
+  if (recalculate_hash)
+    device_encryption_->CalculateHash(data, hash);
   device_encryption_->WriteBlock(ToDeviceSector(block_number), data, iv, encrypt);
 }
 
 bool BlocksDevice::ReadBlock(uint32_t block_number,
+                             uint32_t /*size_in_blocks*/,
                              const std::span<std::byte>& data,
                              const std::span<const std::byte>& hash,
                              uint32_t iv,
                              bool encrypt,
-                             bool check_hash) const {
+                             bool check_hash) {
   device_encryption_->ReadBlock(ToDeviceSector(block_number), data, iv, encrypt);
   return !check_hash || device_encryption_->CheckHash(data, hash);
 }
diff --git a/src/file_device.cpp b/src/file_device.cpp
index 282b21c..2e6935d 100644
--- a/src/file_device.cpp
+++ b/src/file_device.cpp
@@ -10,9 +10,16 @@
 #include <cassert>
 #include <fstream>
 
-FileDevice::FileDevice(const std::string& path, uint32_t log2_sector_size, bool read_only)
-    : file_(new std::fstream(path, std::ios::binary | (!read_only ? (std::ios::out | std::ios::in) : std::ios::in))),
+FileDevice::FileDevice(const std::string& path,
+                       uint32_t log2_sector_size,
+                       uint32_t sectors_count,
+                       bool read_only,
+                       bool create)
+    : file_(new std::fstream(
+          path,
+          std::ios::binary | (!create ? std::ios::in : 0) | ((create || !read_only) ? std::ios::out : 0))),
       log2_sector_size_(log2_sector_size),
+      sectors_count_(sectors_count),
       read_only_(read_only) {
   if (file_->fail()) {
     throw std::runtime_error("FileDevice: Failed to open file");
@@ -29,8 +36,9 @@ FileDevice::FileDevice(const std::string& path, uint32_t log2_sector_size, bool
   sector size)");
   }
   sectors_count_ = static_cast<uint32_t>(file->tellg() >> log2_sector_size);*/
-  sectors_count_ = 0x10;  // we will find the exact sectors count later with
-                          // Wfs::DetectSectorsCount
+  if (sectors_count_ == 0)
+    sectors_count_ = 0x10;  // we will find the exact sectors count later with
+                            // Wfs::DetectSectorsCount
 }
 
 void FileDevice::ReadSectors(const std::span<std::byte>& data, uint32_t sector_address, uint32_t sectors_count) {
diff --git a/src/structs.h b/src/structs.h
index 91858b2..40fbacc 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -83,6 +83,7 @@ struct Attributes {
   bool IsDirectory() const { return !!(flags.value() & Flags::DIRECTORY); }
   bool IsFile() const { return !IsDirectory(); }
   bool IsLink() const { return !!(flags.value() & Flags::LINK); }
+  bool IsQuota() const { return !!(flags.value() & Flags::QUOTA); }
 
   size_t DataOffset() const;
 
diff --git a/src/wfs.cpp b/src/wfs.cpp
index d99fa1c..6b56ee9 100644
--- a/src/wfs.cpp
+++ b/src/wfs.cpp
@@ -19,7 +19,9 @@
 #include "structs.h"
 
 Wfs::Wfs(const std::shared_ptr<Device>& device, const std::span<std::byte>& key)
-    : device_(std::make_shared<BlocksDevice>(device, key)) {
+    : Wfs(std::make_shared<BlocksDevice>(device, key)) {}
+
+Wfs::Wfs(const std::shared_ptr<BlocksDevice>& device) : device_(device) {
   // Read first area
   root_area_ = throw_if_error(Area::LoadRootArea(device_));
 }
diff --git a/src/wfs_item.cpp b/src/wfs_item.cpp
index c01816c..1956df8 100644
--- a/src/wfs_item.cpp
+++ b/src/wfs_item.cpp
@@ -32,6 +32,10 @@ bool WfsItem::IsFile() const {
 }
 
 bool WfsItem::IsLink() const {
+  return attributes_data().Attributes()->IsLink();
+}
+
+bool WfsItem::IsQuota() const {
   auto attributes = attributes_data().Attributes();
-  return attributes->IsLink();
+  return attributes->IsDirectory() && attributes->IsQuota();
 }