Nominatim/docs/admin/Installation.md

Basic Installation

This page contains generic installation instructions for Nominatim and its prerequisites. There are also step-by-step instructions available for the following operating systems:

• Ubuntu 20.04
• Ubuntu 18.04
• CentOS 8
• CentOS 7.2

These OS-specific instructions can also be found in executable form in the vagrant/ directory.

Users have created instructions for other frameworks. We haven't tested those and can't offer support.

• Docker
• Docker on Kubernetes
• Ansible

Prerequisites

Software

For compiling:

• cmake
• expat
• proj
• bzip2
• zlib
• Boost libraries, including system and filesystem
• PostgreSQL client libraries
• a recent C++ compiler (gcc 5+ or Clang 3.8+)

For running Nominatim:

• PostgreSQL (9.3+)
• PostGIS (2.2+)
• Python 3
• Psycopg2
• PHP (7.0 or later)
• PHP-pgsql
• PHP-intl (bundled with PHP)

For running continuous updates:

• pyosmium (with Python 3)

For running tests:

• behave
• nose
• phpunit >= 7.3

Hardware

A minimum of 2GB of RAM is required or installation will fail. For a full planet import 64GB of RAM or more are strongly recommended. Do not report out of memory problems if you have less than 64GB RAM.

For a full planet install you will need at least 800GB of hard disk space (take into account that the OSM database is growing fast). SSD disks will help considerably to speed up import and queries.

Even on a well configured machine the import of a full planet takes at least 2 days. Without SSDs 7-8 days are more realistic.

Tuning the PostgreSQL database

You might want to tune your PostgreSQL installation so that the later steps make best use of your hardware. You should tune the following parameters in your postgresql.conf file.

shared_buffers = 2GB
maintenance_work_mem = (10GB)
autovacuum_work_mem = 2GB
work_mem = (50MB)
effective_cache_size = (24GB)
synchronous_commit = off
checkpoint_segments = 100 # only for postgresql <= 9.4
max_wal_size = 1GB # postgresql > 9.4
checkpoint_timeout = 10min
checkpoint_completion_target = 0.9

The numbers in brackets behind some parameters seem to work fine for 64GB RAM machine. Adjust to your setup. A higher number for max_wal_size means that PostgreSQL needs to run checkpoints less often but it does require the additional space on your disk.

Autovacuum must not be switched off because it ensures that the tables are frequently analysed. If your machine has very little memory, you might consider setting:

autovacuum_max_workers = 1

and even reduce autovacuum_work_mem further. This will reduce the amount of memory that autovacuum takes away from the import process.

For the initial import, you should also set:

fsync = off
full_page_writes = off

Don't forget to reenable them after the initial import or you risk database corruption.

Downloading and building Nominatim

Downloading the latest release

You can download the latest release from nominatim.org. The release contains all necessary files. Just unpack it.

Downloading the latest development version

If you want to install latest development version from github, make sure to also check out the osm2pgsql subproject:

git clone --recursive git://github.com/openstreetmap/Nominatim.git

The development version does not include the country grid. Download it separately:

wget -O Nominatim/data/country_osm_grid.sql.gz https://www.nominatim.org/data/country_grid.sql.gz

Building Nominatim

The code must be built in a separate directory. Create the directory and change into it.

mkdir build
cd build

Nominatim uses cmake and make for building. Assuming that you have created the build at the same level as the Nominatim source directory run:

cmake ../Nominatim
make

Now continue with importing the database.