Whitepaper - Ethereum Classic With Cover

Ethereum Classic Documentation, Release 0.1
--fast
This flag enables fast syncing through state downloads rather than downloading the full block data. This will
also reduce the size of your blockchain dramatically. NOTE: --fast can only be run if you are syncing your
blockchain from scratch and only the first time you download the blockchain for security reasons. See this Reddit
post for more information.
--cache=1024
Megabytes of memory allocated to internal caching (min 16MB / database forced). Default is 16MB, so increasing
this to 256, 512, 1024 (1GB), or 2048 (2GB) depending on how much RAM your computer has should make a
difference.
--jitvm
This flag enables the JIT VM.
Full example command with console:
geth --fast --cache=1024 --jitvm console
For more discussion on fast syncing and blockchain download times, see this Reddit post.
Exporting/Importing the blockchain
If you already have a full Ethereum node synced, you can export the blockchain data from the fully synced node
and import it into your new node. You can accomplish this in geth by exporting your full node with the command
geth export filename and importing the blockchain into your node using geth import filename.
see this link
Static Nodes, Trusted Nodes, and Boot Nodes
Geth supports a feature called static nodes if you have certain peers you always want to connect to. Static nodes
are re-connected on disconnects. You can configure permanent static nodes by putting something like the following
into /static-nodes.json (this should be the same folder that your chaindata and
keystore folders are in)
[
]
"enode://f4642fa65af50cfdea8fa7414a5def7bb7991478b768e296f5e4a54e8b995de102e0ceae2e826f293c4
"enode://pubkey@ip:port"
You can also add static nodes at runtime via the Javascript console using admin.addPeer()
> admin.addPeer("enode://f4642fa65af50cfdea8fa7414a5def7bb7991478b768e296f5e4a54e8b995de102e0ceae2
Common problems with connectivity
Sometimes you just can’t get connected. The most common reasons are:
• Your local time might be incorrect. An accurate clock is required to participate in the Ethereum network.
Check your OS for how to resync your clock (example sudo ntpdate -s time.nist.gov) because
even 12 seconds too fast can lead to 0 peers.
• Some firewall configurations can prevent UDP traffic from flowing. You can use the static nodes feature or
admin.addPeer() on the console to configure connections by hand.
To start geth without the discovery protocol, you can use the --nodiscover parameter. You only want this if
you are running a test node or an experimental test network with fixed nodes.
60 Chapter 1. Contents