Merge pull request 'make lmdb's map_size configurable (fix #628)' (#630) from configurable-map-size into main

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/630

1 files changed, 12 insertions, 3 deletions

diff --git a/doc/book/reference-manual/configuration.md b/doc/book/reference-manual/configuration.md
index b916bb61..08c013f7 100644
--- a/doc/book/reference-manual/configuration.md
+++ b/doc/book/reference-manual/configuration.md
@@ -15,8 +15,9 @@ db_engine = "lmdb"
 
 block_size = 1048576
 
-sled_cache_capacity = 134217728
+sled_cache_capacity = "128MiB"
 sled_flush_every_ms = 2000
+lmdb_map_size = "1T"
 
 replication_mode = "3"
 
@@ -133,8 +134,8 @@ and not just the path to the metadata directory.
 ### `block_size`
 
 Garage splits stored objects in consecutive chunks of size `block_size`
-(except the last one which might be smaller). The default size is 1MB and
-should work in most cases. We recommend increasing it to e.g. 10MB if
+(except the last one which might be smaller). The default size is 1MiB and
+should work in most cases. We recommend increasing it to e.g. 10MiB if
 you are using Garage to store large files and have fast network connections
 between all nodes (e.g. 1gbps).
 
@@ -160,6 +161,14 @@ Increase this if sled is thrashing your SSD, at the risk of losing more data in
 of a power outage (though this should not matter much as data is replicated on other
 nodes). The default value, 2000ms, should be appropriate for most use cases.
 
+### `lmdb_map_size`
+
+This parameters can be used to set the map size used by LMDB,
+which is the size of the virtual memory region used for mapping the database file.
+The value of this parameter is the maximum size the metadata database can take.
+This value is not bound by the physical RAM size of the machine running Garage.
+If not specified, it defaults to 1GiB on 32-bit machines and 1TiB on 64-bit machines.
+
 ### `replication_mode`
 
 Garage supports the following replication modes: