Ethereum Tutorials - Herong's Tutorial Notes - Version 1.01, by Dr. Herong Yang
"geth attach" - Geth Client Console
To avoid data corruptions, on a single Ethereum database, we are not allowed to run two instances of Ethereum node server.
If you have one "geth" command running on the Ethereum database of C:\Users\herong\AppData\Roaming\Ethereum\geth as an Ethereum node server, and you try to start another Ethereum node server on the same database, you will get the following error:
C:\>c:\local\bin\geth --light Maximum peer count ETH=0 LES=100 total=25 Fatal: Error starting protocol stack: datadir already used by another process
In your computer process list, you should see 2 "geth" running: one is the Ethereum node server, the other is the client console.
Last update: 2018.
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