---
title: Installation requirements
description: Canonical makes open source secure, reliable and easy to use, providing
  support for Ubuntu and a portfolio of enterprise-grade technologies. Founded in
  2004, Canonical operates globally with team members in over 80 countries.
url: https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md
---

*Submit*

# Installation requirements

Confirm that your system has adequate resources for your use-case, prior to installation. Proof-of-concept and production setups are available.

## [LXD](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-lxd)

LXD versions older than 5.21 will not work correctly with MAAS.

## [PostgreSQL](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-postgresql)

From version 3.5, MAAS [requires PostgreSQL 14](https://canonical-com-2934.demos.haus/maas/docs/postgresql-deprecation-notices) and a different PostgreSQL default user.

> **Warning**: PostgreSQL defaults may not support HA deployments. Consider using 20-50 extra connections per additional region controller. Check settings using `psql` or by inspecting the configuration file.

### [Getting information using psql](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-getting-information-using-psql)

You can count PostgreSQL connections with this SQL query:

```
SELECT
  max_conn,
  used
FROM
  (SELECT count(*) used FROM pg_stat_activity) t1,
  (SELECT setting::int res_for_super FROM pg_settings WHERE name=$$superuser_reserved_connections$$) t2,
  (SELECT setting::int max_conn FROM pg_settings WHERE name=$$max_connections$$) t3;
```

`max_conn` is the number of available connections; `used` is the number of active connections.

### [Getting information via configuration file](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-getting-information-via-configuration-file)

```
grep 'max_connections' /var/lib/pgsql/{version_number}/data/postgresql.conf
```

### [Increasing maximum connections](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-increasing-maximum-connections)

If `max_connections` is `100`, you need to increase that number. Refer to [these best practices](https://www.postgresql.org/docs/14/runtime-config-connection.html) for details.

### [Symptoms of an issue](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-symptoms-of-an-issue)

Too few database connections tend do produce errors:

```
> FATAL: sorry, too many clients already
> FATAL:  remaining connection slots are reserved for non-replication superuser connections
> pq: remaining connection slots are reserved for non-replication superuser connections
```

## [MAAS, NTP, and chrony](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-maas-ntp-and-chrony)

Conflicts can arise between Ubuntu’s default `systemd-timesyncd` and MAAS `chrony`. Consult the MAAS [installation guide](https://canonical.com/maas/docs/how-to-install-maas) for solutions.

## [Test environment](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-test-environment)

Requirements for a single-host test setup include the latest two Ubuntu LTS releases and the following component settings:

| Component | Memory (MB) | CPU (GHz) | Disk (GB) |
| --- | --- | --- | --- |
| [Region controller](https://canonical.com/maas/docs/cli-region-controller) | 512 | 0.5 | 5 |
| PostgreSQL | 512 | 0.5 | 5 |
| [Rack controller](https://canonical.com/maas/docs/cli-rack-controller) | 512 | 0.5 | 5 |
| Ubuntu Server | 512 | 0.5 | 5 |

Total: 2 GB RAM, 2 GHz CPU, 20 GB disk.

## [Production environment](https://canonical-com-2934.demos.haus/maas/docs/installation-requirements?format=md#p-12448-production-environment)

For large-scale, continuous client handling, plan as follows:

| Component | Memory (MB) | CPU (GHz) | Disk (GB) |
| --- | --- | --- | --- |
| [Region controller](https://canonical.com/maas/docs/cli-region-controller) | 2048 | 2.0 | 5 |
| PostgreSQL | 2048 | 2.0 | 20 |
| [Rack controller](https://canonical.com/maas/docs/cli-rack-controller) | 2048 | 2.0 | 20 |
| Ubuntu Server | 512 | 0.5 | 5 |

Plan for 4.5 GB RAM, 4.5 GHz CPU, and 45 GB disk per host for region controllers, and slightly less for rack controllers.

Additional notes:

* These specs are MAAS-specific and don’t cover extra nodes.
* IPMI-based BMC controllers are recommended for power management.

Factors affecting these numbers:

* Client activity
* Service distribution
* Use of [high availability/load balancing](https://canonical.com/maas/docs/how-to-manage-controllers#p-9026-enable-ha).
* Number and type of stored images
* A local image mirror will increase disk requirements.
* Rack controllers have a 1000-machine cap per subnet

---

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Last updated 1 year, 1 month ago. [Help improve this document in the forum](https://discourse.maas.io/t/installation-requirements/6233).