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, 2 insertions, 0 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 3b1eb6d23..212a1891e 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -40,6 +40,7 @@ set(common_sources
   notify.cpp
   password.cpp
   perf_timer.cpp
+  pruning.cpp
   spawn.cpp
   threadpool.cpp
   updates.cpp
@@ -69,6 +70,7 @@ set(common_private_headers
   http_connection.h
   notify.h
   pod-class.h
+  pruning.h
   rpc_client.h
   scoped_message_writer.h
   unordered_containers_boost_serialization.h