Import blockchain file

Use X-Cash Blockchain Import (xcash-blockchain-import) to import a raw file of the blockchain

Overview

The tool imports a bootstrap file blockchain.raw to your full node to be used as thelmdb blockchain.

This could be useful if you want to decouple download from verification for any reason (like testing performance in isolation), or if you have a limited speed connection. Updated version of the blockchain.raw file can be found on X-Cash communities.

For best practices, you should use your own trusted blockchain.raw file that you exported earlier.

Also note that importing blockchain.raw will in most cases not speed up the process over syncing up from p2p network. This is because usual bottlenecks are disk IO and verification, not the download itself.

The tool works on your local files and does not require xcash running.

Syntax

./xcash-blockchain-import [options]

Example:

./xcash-blockchain-import --help

Running

Go to directory where you unpacked X-Cash.

./xcash-blockchain-import --stagenet --input-file=/tmp/blockchain.raw

Options

Help

Option	Description
--help	Enlist available options.

Pick network

Option	Description
(missing)	By default xcash-blockchain-import assumes the mainnet blockchain.
--stagenet	Import stagenet blockchain.
--testnet	Import testnet blockchain.

Logging

Specifying the log file path is not supported

Option	Description
--log-level	0-4 with 0 being minimal logging and 4 being full tracing. Defaults to 0. These are general presets and do not directly map to severity levels. For example, even with minimal 0, you may see some most important INFO entries. Example: ./xcash-blockchain-import --log-level=1

Input

Option	Description
--data-dir	Full path to data directory. This is where the blockchain, log files, and p2p network memory are stored. For defaults and details see data directory.
--count-blocks	Count blocks in the bootstrap file and exit.
--drop-hard-fork	Whether to drop hard fork data. Off by default (0).
--database	The only valid value seems to be lmdb (the default).

Output

Option	Description
--data-dir	Full path to data directory. This is where the blockchain, log files, and p2p network memory are stored. For defaults and details see data directory.
--count-blocks	Count blocks in the bootstrap file and exit.
--drop-hard-fork	Whether to drop hard fork data. Off by default (0).
--database

Performance

Option	Description
--dangerous-unverified-import	The safe default is to run verification (value 0). You can enable --dangerous-unverified-import if you are importing from your own and trusted blockchain.raw (which we assume was already verified). The "dangerous" mode will greatly speed up the process.
--batch	Whether to save to disk on an ongoing basis (the default, value 1) or maybe do everything in RAM and save everything in the end (value 0). No batching is only effective in combination with no verification (--dangerous-unverified-import). See also --batch-size.
--batch-size	How often to save to disk expressed in number of blocks. By default save every 5000 blocks (when verifying) or every 20000 blocks (when not verifying). Big batches are faster but require more RAM.
--resume	Resume from current height if output database already exists (the default, value 1). Changing to --resume=0 doesn't change much — existing blocks are skipped pretty quickly and the process is resumed anyway.