Reducing Bitcoin Full Node Storage Without Consensus Changes

The recent audit of the BitcoinRocks data directory revealed significant data regarding storage and resource utilization. The entire data directory, after a full synchronization, is approximately 769.904 GB or 717.029 GiB in apparent size, with 717.218 GiB actually allocated on disk. This includes three optional indexes: txindex with 58.391 GiB, blockfilterindex with 12.228 GiB, and coinstatsindex with 0.089 GiB, totaling 70.707 GiB. Without these indexes, the base full-node data directory would be around 693.983 GB or 646.322 GiB.

The main components of the dataset are compressed blk*.dat files which account for 537.005 GiB, rev*.dat files at 98.763 GiB, chainstate at 10.396 GiB, and blocks/index at 0.108 GiB. The audit shows that there is a logical raw block payload of 708.572 GiB stored in 536.988 GiB, achieving a saving of 171.584 GiB or 24.215%. If uncompressed, this would increase the dataset to 888.613 GiB, indicating that compression reduces the entire data directory size by 19.309%.

On the performance front, efforts have been made to optimize Initial Block Download (IBD) by using up to 25% of available system RAM, which allows for a faster synchronization time from Genesis to mainnet, completed in about 30 hours on the tested machine. This approach addresses user complaints about the lengthy sync times typically associated with Bitcoin setup. Despite high RAM usage during IBD, the node's operation became minimally intrusive post-sync, even on a heavily utilized machine.

For accurate comparison and benchmarking against standard Bitcoin Core performance, it is suggested that controlled experiments be conducted considering various factors like hardware, configuration, and network conditions. Ideally, independent reproductions of these tests would provide a robust basis for evaluating relative performance in terms of IBD speed, RAM usage, and runtime efficiency.