---
title: Configure system settings
description: Where to configure systems settings depends on which package you have used to install Elasticsearch, and which operating system you are using. When using...
url: https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/4236/deploy-manage/deploy/self-managed/setting-system-settings
products:
  - Elasticsearch
---

# Configure system settings
Where to configure systems settings depends on which package you have used to install Elasticsearch, and which operating system you are using.
When using the `.zip` or `.tar.gz` packages, system settings can be configured:
- Temporarily with [`ulimit`](#ulimit).
- Permanently in [`/etc/security/limits.conf`](#limits.conf).

When using the RPM or Debian packages, most system settings are set in the [system configuration file](#sysconfig). However, systems which use systemd require that system limits are specified in a [systemd configuration file](#systemd).

## `ulimit`

On Linux systems, `ulimit` can be used to change resource limits on a temporary basis. Limits usually need to be set as `root` before switching to the user that will run Elasticsearch. For example, to set the number of open file handles (`ulimit -n`) to 65,535, you can do the following:
```sh
sudo su  
ulimit -n 65535 
su elasticsearch 
```

The new limit is only applied during the current session.
You can consult all currently applied limits with `ulimit -a`.

## `/etc/security/limits.conf`

On Linux systems, persistent limits can be set for a particular user by editing the `/etc/security/limits.conf` file. To set the maximum number of open files for the `elasticsearch` user to 65,535, add the following line to the `limits.conf` file:
```sh
elasticsearch  -  nofile  65535
```

This change will only take effect the next time the `elasticsearch` user opens a new session.
<admonition title="Ubuntu and limits.conf">
  Ubuntu ignores the `limits.conf` file for processes started by `init.d`. To enable the `limits.conf` file, edit `/etc/pam.d/su` and uncomment the following line:
  ```sh
  # session    required   pam_limits.so
  ```
</admonition>


## Sysconfig file

When using the RPM or Debian packages, environment variables can be specified in the system configuration file, which is located in the relevant location for your package type:

| Package type | Location                       |
|--------------|--------------------------------|
| RPM          | `/etc/sysconfig/elasticsearch` |
| Debian       | `/etc/default/elasticsearch`   |

However, system limits need to be specified via [systemd](#systemd).

## Systemd configuration

When using the RPM or Debian packages on systems that use [systemd](https://en.wikipedia.org/wiki/Systemd), system limits must be specified via systemd.
The systemd service file (`/usr/lib/systemd/system/elasticsearch.service`) contains the limits that are applied by default.
To override them, add a file called `/etc/systemd/system/elasticsearch.service.d/override.conf` (alternatively, you may run `sudo systemctl edit elasticsearch` which opens the file automatically inside your default editor). Set any changes in this file, such as:
```ini
[Service]
LimitMEMLOCK=infinity
```

Once finished, run the following command to reload units:
```sh
sudo systemctl daemon-reload
```