I searched on Reddit, Youtube... but I keep doing something wrong I guess. I downloaded the last Mist, and I want the bundled Geth node to be a light one, and to remain a light client every time I open Mist. Following the tutorials on the web, I simply oper Terminal and type "geth --light", and every time it says "-bash: geth: command not found". Is there something I didn't do right? Can please someone explain me in dumb terms what I have to do?

I have a 2012 MB Pro with MacOS 10.12.5. Thanks

2 Answers 2


The geth install bundled with Mist can't be accessed via "geth" on the command line. Here's what worked for me to get Mist to run as a light client.

Install geth separately. On Ubuntu:

sudo apt-get install software-properties-common
sudo add-apt-repository -y ppa:ethereum/ethereum
sudo apt-get update
sudo apt-get install ethereum

On Mac it should be:

brew update
brew tap ethereum/ethereum
brew install ethereum

Now run geth from the command line in light mode:

geth --syncmode "light" --cache 1024

Once that starts, open up Mist normally and it should connect to the geth light instance automatically. The first time you do this it will redownload the entire blockchain and put it in a separate folder. For me on Ubuntu this is ~.ethereum/geth/lightchaindata whereas the normal chaindata is ~.ethereum/chaindata. The first time will take a couple of minutes to redownload the blockchain (but it's much faster than normal) and after that, it should sync up to the chain in a few seconds.


would you consider using a private network instead?
Syncing the main network may take days and I think it's not necessary if you just want to test the technology.
To run mist on a private net, simply set the ipc path to your_home_dir/Library/Ethereum/geth.ipc
The complete commands for me:
mkdir privchain // for storing your blockchain data
geth --datadir privchain --ipcpath /Users/tina/Library/Ethereum/geth.ipc --networkid 123
Without specifying the network id, it by default will be connected to the main network.

  • This does not answers what I asked, I wanted a simple guide to use Mist in light mode on the main network :) Jul 5, 2017 at 17:41

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