Reduce Memory

There are a few parameters that can be dialed down to reduce the memory usage of bitcoind. This can be useful on embedded systems or small VPSes.

In-memory caches

The size of some in-memory caches can be reduced. As caches trade off memory usage for performance, reducing these will usually have a negative effect on performance.

Memory pool

Number of peers

Thread configuration

For each thread a thread stack needs to be allocated. By default on Linux, threads take up 8MiB for the thread stack on a 64-bit system, and 4MiB in a 32-bit system.

Linux specific

By default, since glibc 2.10, the C library will create up to two heap arenas per core. This is known to cause excessive memory usage in some scenarios. To avoid this make a script that sets MALLOC_ARENA_MAX before starting bitcoind:

#!/usr/bin/env bash

The behavior was introduced to increase CPU locality of allocated memory and performance with concurrent allocation, so this setting could in theory reduce performance. However, in Bitcoin Core very little parallel allocation happens, so the impact is expected to be small or absent.