How to run 2 nodes simultaneously?

Question

I created a Node 0 and exited before creating Node 1. Then I created Node 1. And using Admin API, I connected Node 1 to Node 0.

Node 1 is up and running. How do I start Node 0 and sync it with Node 1?

Or is it already synced?

Thanks.

Edit: This is how I installed ethereum in Lubuntu 16.04

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

Then I ran these commands to create new account

1) geth --datadir ./ account new
2) geth --datadir ./ init customgenesis.json 
3) geth --datadir ./ --networkid 15 --port 30300 console

Now, 3rd command starts a Geth JavaScript console. So I proceed to run 4th command:

4) geth --datadir ./ account new

Upon this, I get this error:

(anonymous): Line 1:8 Unexpected identifier (and 1 more errors)

No problem. I start a new terminal and rerun the 4th command and it runs fine. Now when I run the 5th command,

5) geth --datadir ./ init customgenesis.json 

I get the following error:

Fatal: Failed to open database: resource temporarily unavailable

So I go to first terminal where I created Node 0 and typed exit. Then I reran the 5th commands on the second terminal and command worked. Then I proceeded to run the following commands and they both worked fine:

6) geth --datadir ./ --networkid 15 --port 30301 console

7) admin.addPeer(enode://8cc8dcb50102ac095e6c5de080cff7cc2d66ac4be8093551ba31c60bb315500b68d4cbe2593df6b8e6d35ebd09fb5399a246d67349d9128182caf453df3f3493@127.0.0.1:30300)

Now, what does it mean?

1) Node 0 is off since I exited out of it? 2) Only Node 1 is up? If I understand correctly, both are sharing the same network ID but different ports, hence there shouldn't be any problem running both nodes?

Any insight would be appreciated. Thanks.

Answer 1

Your problem as i understand it is using two nodes with the same data directory (--datadir) which is impossible !!

to run two nodes you have to use two different directories and different ports.

First initiate a node

geth -verbosity 3 --datadir="./node1" init genesis.json 

Then run it

geth -verbosity 3 --datadir="./node1" --networkid 15 --ipcdisable --port 30301 console 

Then run the second node in the same way on a different port (30302) and different datadir --datadir="./node2"