geth - web3 : checkBalance not supported

Question

Here is what I did :

Terminal 1 :

geth --syncmode "light"

Terminal 2 :

geth attach
> web3.fromWei(eth.getBalance(eth.coinbase), "ether")
Error: not supported
    at web3.js:3104:20
    at web3.js:6191:15
    at get (web3.js:6091:38)
    at <unknown>

What am I missing?

Answer 1

Not using light sync mode and not using web3js, but it works for me. Perhaps update geth to the latest version (my version is: Geth/v1.8.27-stable/linux-amd64/go1.10.5)

# geth attach http://127.0.0.1:8545/
> web3.fromWei(eth.getBalance(eth.coinbase), "ether")
4710

and I'm on a private network >:)