Pruning

The blockchain prunes seven eighths of prunable tx data.
This saves about two thirds of the blockchain size, while
keeping the node useful as a sync source for an eighth
of the blockchain.

No other data is currently pruned.

There are three ways to prune a blockchain:

- run monerod with --prune-blockchain
- run "prune_blockchain" in the monerod console
- run the monero-blockchain-prune utility

The first two will prune in place. Due to how LMDB works, this
will not reduce the blockchain size on disk. Instead, it will
mark parts of the file as free, so that future data will use
that free space, causing the file to not grow until free space
grows scarce.

The third way will create a second database, a pruned copy of
the original one. Since this is a new file, this one will be
smaller than the original one.

Once the database is pruned, it will stay pruned as it syncs.
That is, there is no need to use --prune-blockchain again, etc.

1 files changed, 33 insertions, 0 deletions

diff --git a/src/blockchain_utilities/CMakeLists.txt b/src/blockchain_utilities/CMakeLists.txt
index ddf575c29..df74eb695 100644
--- a/src/blockchain_utilities/CMakeLists.txt
+++ b/src/blockchain_utilities/CMakeLists.txt
@@ -92,6 +92,17 @@ monero_private_headers(blockchain_prune_known_spent_data
 
 
 
+set(blockchain_prune_sources
+  blockchain_prune.cpp
+  )
+
+set(blockchain_prune_private_headers)
+
+monero_private_headers(blockchain_prune
+	  ${blockchain_prune_private_headers})
+
+
+
 set(blockchain_ancestry_sources
   blockchain_ancestry.cpp
   )
@@ -298,3 +309,25 @@ set_property(TARGET blockchain_prune_known_spent_data
 	PROPERTY
 	OUTPUT_NAME "monero-blockchain-prune-known-spent-data")
 install(TARGETS blockchain_prune_known_spent_data DESTINATION bin)
+
+monero_add_executable(blockchain_prune
+  ${blockchain_prune_sources}
+  ${blockchain_prune_private_headers})
+
+set_property(TARGET blockchain_prune
+	PROPERTY
+	OUTPUT_NAME "monero-blockchain-prune")
+install(TARGETS blockchain_prune DESTINATION bin)
+
+target_link_libraries(blockchain_prune
+  PRIVATE
+    cryptonote_core
+    blockchain_db
+    p2p
+    version
+    epee
+    ${Boost_FILESYSTEM_LIBRARY}
+    ${Boost_SYSTEM_LIBRARY}
+    ${Boost_THREAD_LIBRARY}
+    ${CMAKE_THREAD_LIBS_INIT}
+    ${EXTRA_LIBRARIES})