diff --git a/README.md b/README.md
index 82655d32c..63a1c4801 100644
--- a/README.md
+++ b/README.md
@@ -58,11 +58,15 @@ If you have already cloned the repo and forgot to pass `--recurse-submodules`, e
 
 ```
 sudo apt update
-sudo apt install autoconf build-essential cmake libprocps-dev libtool texinfo wget yasm flex bison btrfs-progs 
+sudo apt install autoconf build-essential cmake libprocps-dev libtool texinfo wget yasm flex bison btrfs-progs python python3-pip gawk git vim doxygen 
 sudo apt install make build-essential cmake pkg-config libgnutls28-dev libssl-dev unzip zlib1g-dev libgcrypt20-dev docker.io gcc-9 g++-9 gperf clang-format-11 gnutls-dev
+sudo apt install nettle-dev libhiredis-dev redis-server google-perftools libgoogle-perftools-dev lcov
 ```
 
-NB cmake needs to be of version >=3.31, git of version >=2.18
+
+
+
+NB cmake needs to be of version >=3.21, git of version >=2.18
 
 ### (for Ubuntu 20.10 or later) Set  gcc-9 as default compiler
 ```
@@ -74,14 +78,15 @@ sudo update-alternatives --install /usr/bin/gcov-tool gcov-tool /usr/bin/gcov-to
 gcc --version
 ```
 
-### Build dependencies
+# Install latest cmake 
 
 ```
-cd deps
-./build.sh
+sudo apt-get purge cmake
+sudo snap install cmake --classic
 ```
 
-or, if you want to build debug version of skaled
+
+### Build dependencies
 
 ```
 cd deps
@@ -107,8 +112,6 @@ cmake -H. -Bbuild -DCMAKE_BUILD_TYPE=Debug
 cmake --build build -- -j$(nproc)
 ```
 
-Note: Currently only Debug build is supported.
-
 
 ## Testing
 
diff --git a/deps/build.sh b/deps/build.sh
index f8a184049..16f35d527 100755
--- a/deps/build.sh
+++ b/deps/build.sh
@@ -932,13 +932,8 @@ then
 		cd "$SOURCES_ROOT"
 		if [ ! -d "libiconv-1.15" ];
 		then
-			if [ ! -f "libiconv-1.15.tar.gz" ];
-			then
-				echo -e "${COLOR_INFO}downloading it${COLOR_DOTS}...${COLOR_RESET}"
-				eval "$WGET" --no-check-certificate https://ftp.gnu.org/pub/gnu/libiconv/libiconv-1.15.tar.gz
-			fi
 			echo -e "${COLOR_INFO}unpacking it${COLOR_DOTS}...${COLOR_RESET}"
-			eval tar -xzf libiconv-1.15.tar.gz
+			eval tar -xzf "$PREDOWNLOADED_ROOT/libiconv-1.15.tar.gz"
 			echo -e "${COLOR_INFO}configuring it${COLOR_DOTS}...${COLOR_RESET}"
 			cd libiconv-1.15
 			eval ./configure "${CONF_CROSSCOMPILING_OPTS_GENERIC}" --enable-static --disable-shared --prefix="$INSTALL_ROOT" "${CONF_DEBUG_OPTIONS}"
diff --git a/deps/pre_downloaded/libiconv-1.15.tar.gz b/deps/pre_downloaded/libiconv-1.15.tar.gz
new file mode 100644
index 000000000..abdb6a4f1
Binary files /dev/null and b/deps/pre_downloaded/libiconv-1.15.tar.gz differ
diff --git a/libdevcore/LevelDB.cpp b/libdevcore/LevelDB.cpp
index 5b29b04f3..2a67bc5ea 100644
--- a/libdevcore/LevelDB.cpp
+++ b/libdevcore/LevelDB.cpp
@@ -89,7 +89,7 @@ leveldb::ReadOptions LevelDB::defaultReadOptions() {
 
 leveldb::WriteOptions LevelDB::defaultWriteOptions() {
     leveldb::WriteOptions writeOptions = leveldb::WriteOptions();
-    writeOptions.sync = true;
+    //    writeOptions.sync = true;
     return writeOptions;
 }
 
diff --git a/libethereum/BlockChain.cpp b/libethereum/BlockChain.cpp
index 8902b8ff0..fcca55c02 100644
--- a/libethereum/BlockChain.cpp
+++ b/libethereum/BlockChain.cpp
@@ -1263,7 +1263,8 @@ void BlockChain::garbageCollect( bool _force ) {
 
     m_lastCollection = chrono::system_clock::now();
 
-    while ( m_lastStats.memTotal() >= c_maxCacheSize ) {
+    // We subtract memory that blockhashes occupy because it is treated sepaparately
+    while ( m_lastStats.memTotal() - m_lastStats.memBlockHashes >= c_maxCacheSize ) {
         Guard l( x_cacheUsage );
         for ( CacheID const& id : m_cacheUsage.back() ) {
             m_inUse.erase( id );
@@ -1316,6 +1317,7 @@ void BlockChain::garbageCollect( bool _force ) {
 
     {
         WriteGuard l( x_blockHashes );
+        // This is where block hash memory cleanup is treated
         // allow only 4096 blockhashes in the cache
         if ( m_blockHashes.size() > 4096 ) {
             auto last = m_blockHashes.begin();
diff --git a/libskale/State.cpp b/libskale/State.cpp
index 70f32d45f..5bf4433d5 100644
--- a/libskale/State.cpp
+++ b/libskale/State.cpp
@@ -801,8 +801,19 @@ void State::clearStorage( Address const& _contract ) {
     for ( auto const& hashPairPair : storage_WITHOUT_LOCK( _contract ) ) {
         auto const& key = hashPairPair.second.first;
         auto const& value = hashPairPair.second.first;
+        // Set storage to zero in state cache
         clearStorageValue( _contract, key, value );
+        // Set storage to zero in the account storage cache
+        // we have lots of caches, some of them may be unneeded
+        // will analyze this more in future releases
         acc->setStorageCache( key, 0 );
+        /* The corresponding key/value pair needs to be cleared in database
+           Inserting ZERO deletes the key during commit
+           at the end of transaction
+           see OverlayDB::commitStorageValues()
+        */
+        h256 ZERO( 0 );
+        m_db_ptr->insert( _contract, key, ZERO );
     }
 
     totalStorageUsed_ -= ( accStorageUsed + storageUsage[_contract] );