Introduction

The blockchain utilities allow one to import and export the blockchain.

Usage:

See also each utility's "--help" option.

Export an existing blockchain database

$ electroneum-blockchain-export

This loads the existing blockchain and exports it to $ELECTRONEUM_DATA_DIR/export/blockchain.raw

Import the exported file

$ electroneum-blockchain-import

This imports blocks from $ELECTRONEUM_DATA_DIR/export/blockchain.raw (exported using the electroneum-blockchain-export tool as described above) into the current database.

Defaults: --batch on, --batch size 20000, --verify on

Batch size refers to number of blocks and can be adjusted for performance based on available RAM.

Verification should only be turned off if importing from a trusted blockchain.

If you encounter an error like "resizing not supported in batch mode", you can just re-run the electroneum-blockchain-import command again, and it will restart from where it left off.

## use default settings to import blockchain.raw into database
$ electroneum-blockchain-import
 
## fast import with large batch size, database mode "fastest", verification off
$ electroneum-blockchain-import --batch-size 20000 --database lmdb#fastest --verify off

Import options

--input-file specifies input file path for importing

default: <data-dir>/export/blockchain.raw

--output-file specifies output file path to export to

default: <data-dir>/export/blockchain.raw

--block-stop stop at block number

--database <database type>

--database <database type>#<flag(s)>

database type: lmdb, memory

flags:

The flag after the # is interpreted as a composite mode/flag if there's only one (no comma separated arguments).

The composite mode represents multiple DB flags and support different database types:

safe, fast, fastest

Database-specific flags can be set instead.

LMDB flags (more than one may be specified):

nosync, nometasync, writemap, mapasync, nordahead

Examples:

$ electroneum-blockchain-import --database lmdb#fastest
 
$ electroneum-blockchain-import --database lmdb#nosync
 
$ electroneum-blockchain-import --database lmdb#nosync,nometasync