@@ -19,9 +19,9 @@ namespace Nethermind.Db
 {
     public static class MetadataDbKeys
     {
-        public static byte[] FinalizedBlockHash = { 1 };
+        public const int FinalizedBlockHash = 1;
         public const int ConfirmedBlockHash = 2;
-        public const long TerminalTotalDifficulty = 3;
+        public const int TerminalTotalDifficulty = 3;
         public const int TerminalPoWHash = 4;
         public const int FirstPoSBlockHash = 5;
     }
﻿//  Copyright (c) 2021 Demerzel Solutions Limited
//  This file is part of the Nethermind library.
// 
//  The Nethermind library is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
// 
//  The Nethermind library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
//  GNU Lesser General Public License for more details.
// 
//  You should have received a copy of the GNU Lesser General Public License
//  along with the Nethermind. If not, see <http://www.gnu.org/licenses/>.
// 

namespace Nethermind.Db
{
    public static class MetadataDbKeys
    {
        public static byte[] FinalizedBlockHash = { 1 };
        public const int ConfirmedBlockHash = 2;
        public const long TerminalTotalDifficulty = 3;
        public const int TerminalPoWHash = 4;
        public const int FirstPoSBlockHash = 5;
    }
}

The most important thing is saving FinalizedBlockHash and FirstPoSBlock. I have a question mark about TerminalPoW.