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History

Thomas Winget 7b14d4a17f Steps toward multiple dbs available -- working There will need to be some more refactoring for these changes to be considered complete/correct, but for now it's working. new daemon cli argument "--db-type", works for LMDB and BerkeleyDB. A good deal of refactoring is also present in this commit, namely Blockchain no longer instantiates BlockchainDB, but rather is passed a pointer to an already-instantiated BlockchainDB on init().		2015-03-25 12:09:44 -04:00
..
blockchain_converter.cpp	blockchain_converter: Add support for resume from last block	2015-03-23 18:52:55 -07:00
blockchain_export.cpp	blockchain_export: show progress during export	2015-03-22 15:45:37 -07:00
blockchain_export.h	blockchain_export: Add compile-time support for BlockchainDB	2015-03-16 11:57:26 -07:00
blockchain_import.cpp	blockchain_import: lengthen string for line clear	2015-03-22 15:45:37 -07:00
CMakeLists.txt	Add blockchain_export utility	2015-03-16 00:26:59 -07:00
fake_core.h	Steps toward multiple dbs available -- working	2015-03-25 12:09:44 -04:00
import.h	Add blockchain_import utility	2015-03-16 00:26:51 -07:00
README.md	Add README for blockchain converter, importer, and exporter utilities	2015-03-22 15:45:25 -07:00

README.md

For importing into the LMDB database, compile with DATABASE=lmdb

e.g.

DATABASE=lmdb make release

This is also the default compile setting on the blockchain branch.

By default, the exporter will use the original in-memory database (blockchain.bin) as its source. This default is to make migrating to an LMDB database easy, without having to recompile anything. To change the source, adjust SOURCE_DB in src/blockchain_converter/blockchain_export.h according to the comments.

Usage:

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

Export an existing in-memory database

$ blockchain_export

This loads the existing blockchain, for whichever database type it was compiled for, and exports it to $MONERO_DATA_DIR/export/blockchain.raw

Import the exported file

$ blockchain_import

This imports blocks from $MONERO_DATA_DIR/export/blockchain.raw 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.

# use default settings to import blockchain.raw into database
$ blockchain_import

# fast import with large batch size, verification off
$ blockchain_import --batch-size 100000 --verify off

# LMDB flags can be set by appending them to the database type:
# flags: nosync, nometasync, writemap, mapasync
$ blockchain_import --database lmdb#nosync
$ blockchain_import --database lmdb#nosync,nometasync

Blockchain converter with batching

blockchain_converter has also been updated and includes batching for faster writes. However, on lower RAM systems, this will be slower than using the exporter and importer utilities. The converter needs to keep the blockchain in memory for the duration of the conversion, like the original bitmonerod, thus leaving less memory available to the destination database to operate.

$ blockchain_converter --batch on --batch-size 20000