‘Pruning’ allows Monero node operators to save 2/3 of storage space while keeping the full transaction history. Pruning works by removing 7/8 of unnecessary ring signature data. The 1/8 remaining data will be available to the other nodes and used to sync with the network. Other pruned nodes will have a random 1/8 of the data, which they will also make available to the network. There are no privacy or security downsides when using a pruned node.
There are three ways to prune:
- Synchronize a pruned node from scratch: You will download and sync only 1/3 of the full blockchain.
- Prune an existing node: The existing blockchain will be pruned, which will not result in a smaller one. Instead, it will mark parts of the file as free so that future data will use that free space, causing the file not to grow until free space grows scarce.
- Create a new pruned blockchain from a full one: A complete blockchain that you already have will be used to create a new, pruned blockchain.
Pruned nodes are very useful and preferable to remote nodes, but if possible, users should run a full node and opt for pruning only in case necessary.
The ‘database pruning’ feature was added on January 2019. See the blog post for more information.
