If you've set your Ethereum (geth) wallet to light mode in order to save on drive space, the trade-off can be fewer light peers on the Ethereum network that it can connect to, resulting in occasional network difficulties.
Further, light mode is not ideal for ETH cash-out on two-way machines. This is because fast mode will detect users' deposits once they're broadcast, moving the machine to the 'Authorising' screen, thereby prompting the user to wait for a confirmation before the machine dispenses.
Running light mode on the other hand, won't trigger the 'Authorising' screen and only updates the machine's screen once it begins dispensing following a confirmation, leading to potentially confused users who didn't know to wait at the machine.
In recent geth versions, it's been observed that the fast mode blockchain requirements are much reduced, down from close to 300 GB to around 80 GB. We're still confirming this default behaviour, though so far this would make fast mode more reasonable to run for both one-way and two-way machines.
Verifying the current mode
In your server, run:
ps aux | grep geth
Look for the syncmode flag. If it says 'light', proceed with the rest of this article. If 'fast', only update your geth version (below).
Use this article to ensure you're on the latest Geth version prior to switching modes: Updating the Ethereum wallet (geth)
Ensure that you have at least an additional 100 GB free on your block storage volume.
In the server, display the current volume usage with the following, looking for the /dev/sda (/mnt/blockchains) entry:
If you need more space see our article on resizing your block storage volume.
Setting to fast mode
To set geth to fast mode, we'll change two configuration files and reboot the droplet.
CAUTION: Rebooting the droplet can sometimes result in wallets such as BTC's reindexing their blockchains, in which case those coins would only be available to serve users after resyncing, which could take hours. It's best to do the following during a slow period or after-hours.
In the server, run:
curl -sS https://raw.githubusercontent.com/naconner/lamascripts/master/switches/fast/fast.sh | bash
Your server will log you out of the terminal as your droplet reboots.
Checking for success
After a minute, log back in to your server, and check the status of Ethereum with:
You may then check Ethereum's sychronization status.
Further, keep tabs on your volume's disk usage with the prior df -h command in order to ensure you don't run out of space.