I used to initialise a private blockchain in this way:

geth --identity "Prashant" --fast --cache=1024 --jitvm --rpc  --rpcport "8013" --rpccorsdomain "*" --datadir "myPrivateNetwork2" --port "30312"  --ipcapi "admin,db,eth,debug,miner,net,shh,txpool,personal,web3" --rpcapi "db,eth,net,web3,admin,debug,miner,personal,web3" --autodag --networkid 1902 --nat "any" init customGenesis.json console   

I tried that again after a long time and I am getting an error message stating that --jitvm, --ipcapi, --autodag flags are provided but no defined.

Are these flags completely deprecated, or are there alternatives? How can I specify whatipc apis I need to expose?

I am also getting this issue:

Fatal: invalid genesis file: hex string has odd length

My genesis.json is this:

    "nonce": "0x0000000000000042",
    "timestamp": "0x0",
    "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "extraData": "0x0",
    "gasLimit": "0x8000000",
    "difficulty": "0x400",
    "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
    "coinbase": "0x3333333333333333333333333333333333333333",

I have read other threads on the Genesis issue, all suggesting to use the latest version of geth, but I am already using it.

The genesis issue was resolved by making extraData value an even length (0x00), as well as I needed to add a config to the customGenesiss.json,

    "extraData": "0x00",
    "config": {
            "chainId": 15,
            "homesteadBlock": 0,
            "eip155Block": 0,
            "eip158Block": 0
  • Can you try making the extraData value an even length? (e.g. 0x00.) Commented Jun 4, 2017 at 7:23
  • Making it even worked. But now it's : failed to write genesis block: genesis has no chain configuration. And if you could explain why I need to make it even. Commented Jun 4, 2017 at 10:44
  • which version do you have? because i've tried same options with geth 1.5.9-stable and it didn't raise any error
    – Badr Bellaj
    Commented Jun 4, 2017 at 12:01
  • I have geth 1.6.0-stable-facc47cb. A lot of things changes when you come back to ethereum after some time :p Commented Jun 4, 2017 at 12:55

1 Answer 1


A partial answer...

The jitvm flag is deprecated. See #2365, though it was actually removed as part of #13875.

The autodag flag is also deprecated, and is now the default behaviour. See the thread for #3768. (I can't immeidately find when it was removed, though.)

  • 1
    strange but they are still listed in geth help!!
    – Badr Bellaj
    Commented Jun 4, 2017 at 11:56

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