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OpenSimulator simulator configuration file

The region simulator configuration is managed using a file called OpenSim.ini. This file is used regardless of whether the sim is running in standalone or grid mode. This file references some additional configuration information from the config-include/ directory. Information about the various settings is contained in the OpenSim.ini file itself (or OpenSim.ini.example for reference).

Please note, that the name OpenSim.ini can be changed via command line arguments.

It is also possible to distribute the inifile settings over two files. This is useful if you want to run several OpenSimulator processes where most of your settings are identical except for a few. The master file is read first, then the inifile is read. Settings given in the inifile overrule settings given in the master file. The master file has the same format and the same keywords as the inifile, so the same documentation applies.


Opensimulator supports the following database engines. Information about setting these up can be found in the OpenSim.ini.example file and the other various example files in bin/config-include. If you do not want to use the default SQLite configuration then you will need to setup your database before proceeding further. SQLite does not require further configuration. See Database Settings for the detailed settings.

  • SQLite (default) - a lightweight database that comes bundled with OpenSimulator and can be used without requiring any extra configuration. It is mostly intended to get you up and running quickly, not for production use. It is significantly slower than MySQL. A few features here (such as attachment persistence) have not yet been fully implemented.
  • MySQL (fully supported) - This is the recommended database for any use beyond experimentation or small standalone applications. The minimum MySQL version is 5.1.
  • MariaDB (fully supported) - A compatible alternative to MySQL. You need to make sure the selected charset is utf8mb3 (ie 3 bytes). Some instalations default to uft8mb4 (4 bytes) and that will fail
  • MSSQL (fairly supported) - persistence support for some recent OpenSimulator features may not yet be implemented though the vast majority of them are supported.

Standalone vs. Grid

We recommend that you first get OpenSimulator running in standalone mode before you attempt to connect it to a grid or run your own grid. OpenSimulator will start up in standalone mode out-of-the-box on the binary distributions.

An OpenSimulator configuration consists of regions (run by region simulators) and backend data services (such as user, assets and inventory management).

A system running in standalone mode runs both the region simulator and all the data services in a single process when you run OpenSim.exe. In this mode you can run as many regions as you like but only on a single machine.

OpenSimulator running in standalone mode. Both simulator and services run in the same process (OpenSim.exe).

In grid mode, the data services are not part of the region server process. Instead, they are run in a separate executable called Robust.exe. A Robust shell can run all the services or they can be split amongst any number of Robust instances. This allows them to be run on entirely separate machines if necessary. In this mode, the OpenSim.exe acts solely as the region server, serving one or more regions that communicate with the separate data services. At this point you can run multiple OpenSim.exe region simulators on different machines.

OpenSimulator running in grid mode. In this case, all the services are being run within a Robust.exe process. Multiple copies of OpenSim.exe (usually running on different machines) all use the same set of common services.

Running in grid mode is more complicated than running in standalone mode. It requires an understanding of UUID, X,Y location, server handshake passwords, estates and estate owners, and a couple of other settings. These require more care and patience to set up. We strongly recommend that you don't attempt this unless you are extremely patient and very technically proficient.

Running OpenSimulator in Standalone mode

Binary distributions of OpenSimulator are by default configured to run in standalone mode. For versions up to you need also to edit bin/OpenSim.ini to change PublicPort = 8002 to PublicPort = 9000.

However, if you build OpenSimulator from the source distribution or from the git repository then you will need to:

  1. Change into the bin folder
  2. Copy the file OpenSim.ini.example to OpenSim.ini. This configures the 3D simulator itself.
  3. Check the [Const] section PublicPort. It should be set to 9000 by default for a standalone.
  4. In the [Architecture] section of OpenSim.ini, near the bottom of the file, uncomment the Standalone.ini line. To uncomment a line of code, remove the semi-colon (;) comment symbol preceding the line.
  5. Change into the bin/config-include folder
  6. Copy the file StandaloneCommon.ini.example to StandaloneCommon.ini. This configures the in-process data services used by the standalone configuration.
  7. Copy the file FlotsamCache.ini.example to FlotsamCache.ini. This configures the cache services used by the standalone configuration.

Running OpenSimulator is then a matter of launching OpenSim.exe. However, you need to have installed all dependencies before that. See Dependencies for details. After that, open a command prompt (for Windows users, Start menu > Run > cmd) and navigate to the Opensim /bin directory.

Under Windows, run:


On Linux run:

mono OpenSim.exe

Running for the first time

If you're running OpenSimulator for the first time, it will ask you several questions at the console that will set up a single region for you. The configuration options you enter will be written to the bin/Regions/Regions.ini file, which you can then edit at a later date if you need to make changes.

Many of the questions have defaults. Here are some explanations of the questions asked:

  • New region name
The name for your region. Don't leave this blank!
  • Region UUID
The unique ID of your region. In pretty much all cases you will want to accept the randomly generated default in the square brackets. The only time when you wouldn't is if you were trying to set up a configuration to point to pre-existing region data. But in this case you are probably better off editing the Regions.ini file directly anyway
  • Region Location
This is the location of the region on the grid. In standalone mode you can safely leave these as the default (1000,1000). If you were to set up additional regions later on in Regions.ini then they would need different grid co-ordinates (e.g. 1000,1001). OpenSimulator regions can be placed anywhere on a 65536 by 65536 grid, but Hypergrid enabled regions may need special consideration for region location. See Installing and Running Hypergrid#The 4096 Regions Limit for more information.
  • Internal IP address
In virtually all cases this can be left as (this is a wildcard that allows OpenSimulator to listen for UDP connections on any of the server's network interfaces). If you want to restrict UDP connections to only one network interface then you can specify an explicit IP address. This address is only used internally - the External host name is the one that is actually passed to the viewer (and hence is the important one).
  • Internal port
This is the IP port for all incoming client connections. The name is a bit misleading since it will be used externally (by a Second Life viewer, for instance) as well as internally. You can make this any port you want, but it is safe to leave at the default 9000. Each region on your server must have a unique port.
  • Allow alternate ports
This is currently experimental. Please leave it at the default of False.
  • External host name
If you leave this at the default 'SYSTEMIP' then this will become the LAN network address of the machine (e.g. This is fine if you are connecting only from within your LAN. If you want to connect to it from a client on the internet, this should be the External IP Address of your router. Fully Qualified Domain Names (FQDNs) can also be used though they will be converted to a numeric IP address before being sent to the viewer.

OpenSimulator will ask you to assign each region to an estate during the setup process. If an estate needs to be created then it will also ask you to assign an estate manager. In standalone mode, an estate manager can also be created during the setup process.

Don't forget the account details you use to set up the master avatar (in 0.6.9) or the estate manager (in 0.7 and later). Only this user will initially be able to configure the in-world settings for your region. This is also a user account that you can use to perform your initial login test.

See Configuring Regions for more information about the Regions.ini file that these questions generate.

If you want to create a user other than the estate manager, then in the server console type:

create user

This will ask you a series of questions for creating a user (such as first name, last name and password).

Network access for the standalone installation

In standalone mode, a viewer connecting to your installation needs the following network access to your installation machine.

1. TCP over the http_listener_port as used in your simulator. This is set in the [Network] section of your OpenSim.ini.

http_listener_port = 9000

This will be the default of 9000 if you have not explicitly changed it.

Set PublicPort to same port in section [Const]

PublicPort = 9000

2. UDP over each region's InternalPort as configured in your region files (such as Regions.ini). For instance, if you have configured

RegionUUID = dd5b77f8-bf88-45ac-aace-35bd76426c81
Location = 1000,1000
SizeX = 256
SizeY = 256
SizeZ = 256
InternalAddress =
InternalPort = 9000
AllowAlternatePorts = False
ExternalHostName =

RegionUUID = dd5b77f8-bf88-45ac-aace-35bd76426c82
Location = 1000,1001
SizeX = 256
SizeY = 256
SizeZ = 256
InternalAddress =
InternalPort = 9001
AllowAlternatePorts = False
ExternalHostName =

then you will need to open ports 9000 and 9001 to UDP traffic.

3. The network address of the machine hosting the OpenSimulator installation must be accessible to connecting viewers. In the example above, the installation machine is reachable from the Internet via the domain name "". If the same installation needs to be accessed by viewers on the same network, it must be possible for them to also successfully resolve that domain name (not all routers, especially home routers, have this "loopback capability").

If the installation only needed to be accessed on the same LAN, then one could you the local IP address of the server (e.g.

Connecting to a standalone installation

To connect to your new sim with your user, start up a viewer with the following command line switches:

Client on same machine as OpenSim:


Client on same LAN as OpenSim:

-loginuri http://lan_ip:9000

Client on different machine or internet:

-loginuri http://external_ip:9000

Then enter the user name and password you set up in the previous step and your new user should login.

Be aware of loopback problems when Running viewer & server(s) on the same machine (LAN) by using the "external" configuration. (You might notice endless waiting for region handshake.) See also troubleshoot hints. If you're having Connectivity problems, be sure to read the Network Configuration Page. This is important if you see Region handshake issue.


If you download the latest version of, it is necessary to first launch the setup program configure.exe

  • In Linux or MacOSX : open a terminal and enter "mono /diva-r18611/bin/Configure.exe" (assuming that you have placed the Diva distro in /diva-r18611)
  • In Windows, assuming they extracted Diva in My Documents, one would open "Run => cmd" and enter 'cd "%USERPROFILE%\My Documents\diva-r18611\", followed by "Configure.exe".

After issuing the command, you can set your sim's domain name, and carefully answer the program's questions, then start the program as instructed in above paragraphs.

The program will install the optimum configuration for OpenSim, example: http://<your_IP>:9000 and WiFi http:<your_IP>:9000/wifi In the standalone version, four regions will be set up. You can optionally add other regions later on, so make sure to use the same first name with the addition of a number (ex: "region 5", "region 6", "region 7", etc. otherwise you can't enter the region and you'd be placed in the nearest free location.

If you wish to enter a different region name, make sure that the "distance" between the island created by the Wifi configuration program and the next, 
will be at least 40 positions away from the first installed region)
(command console: create region Johnnyland RegionConfigure.ini)

Running OpenSimulator in Grid mode

Running OpenSimulator in grid mode is considerably more complicated than running a standalone instance. Instead of running everything in the same process, backend data services (asset, inventory, etc.) run in one or more separate processes, often on a different machine. This allows multiple OpenSim.exe simulator instances to use the same asset and inventory data.

Step 1: Set up a ROBUST services instance

1. In the bin directory, copy Robust.ini.example to Robust.ini. The example file is configured to run all the services in a single ROBUST instance.

2. Configure the Database Settings in Robust.ini to use your MySQL database. Only MySQL is supported for running grid services.

3. Start up Robust.exe.

mono Robust.exe (Linux, BSD, Mac OS X)


Robust.exe (Windows)

If you don't see any errors (in red) on the console then you can move on to the next step.

4. Every region must belong to an estate, and every estate must have an owner which is a valid user account in OpenSim's user account service. Create a user on the ROBUST command console with the following command.

create user

This will ask you for the user's name, password and an optional e-mail. Remember this name since you will need it when you start up the simulator for the first time.

Step 2: Configure an OpenSim.exe to use the ROBUST services

In grid mode, as in standalone mode, you need to configure OpenSim.ini which controls the 3D simulator itself.

However, instead of using and configuring the file config-include/StandaloneCommon.ini, a simulator connecting to a grid needs to use and configure the config-include/GridCommon.ini file, in order to connect to the ROBUST hosted remote data services rather than in-process local ones.

The steps for both these operations are as follows.

1. Copy bin/OpenSim.ini.example to OpenSim.ini

2. Find the [Const] section near top of the file and set the parameters match the grid services ports, in case of a simple grid configuration

BaseHostname = ""
PublicPort = "8002"
PrivatePort = "8003"

3. Find the [Architecture] section at the very bottom of OpenSim.ini. Make sure that one of the following lines is uncommented:

Include-Architecture = "config-include/Grid.ini" (in OpenSimulator 0.7.1 and later)


Include-Grid         = "config-include/Grid.ini" (in OpenSimulator and earlier)

The others should remain commented.

3. Go to bin/config-include and copy GridCommon.ini.example to GridCommon.ini.

4. Open GridCommon.ini in a text editor. You will see lots of URL entries, each of which have defaults of ${Const|BaseURL}:${Const|PublicPort} or ${Const|BaseURL}:${Const|PrivatePort}, or, on older versions, just dummy urls like, etc. You may will need to change some of these to point towards the address of the respective grid service url. For instance, grid may run assets server on a machine with a address of, you will need to change AssetServerURI to the setting

AssetServerURI = ""

5. Run OpenSim.exe. If you're running OpenSim.exe for the first time you will get the same questions about setting up the region that occur on a first-run in standalone mode. Please see the standalone section for instructions on how to answer these, or read more information about the Regions.ini file on the Configuring Regions page.

If everything is set up correctly, when starting up OpenSim.exe you shouldn't see any errors. You should also see the ROBUST console display log lines saying that the region has registered with the grid service. For example,

21:43:45 - [GRID SERVICE]: Region t1 (176cc95e-f693-4b02-8e08-af86e2372faa) registered successfully at 256000-256000
21:43:47 - [GRID SERVICE]: region t1 has 0 neighbours

Network access for a grid installation

In standalone mode, a viewer connecting to your installation needs to access

  1. The login service over TCP and other configured public services (e.g. grid info, map).
  2. The http_server_port of each configured simulator over TCP.
  3. The InternalPort and ExternalHostName of each configured region.

The last two requirements are the same as for standalone installations, except that they apply to each server that hosts a simulator. Please see the standalone section above for more details.

The login service is a little different. Whereas in standalone this uses the same http_server_port as the simulator itself, in grid mode it's running in a separate ROBUST service.

The default port for the login service is 8002. You can see this used in the [ServiceList] section of Robust.ini.example.

AssetServiceConnector = "8003/OpenSim.Server.Handlers.dll:AssetServiceConnector"
InventoryInConnector = "8003/OpenSim.Server.Handlers.dll:XInventoryInConnector"
GridServiceConnector = "8003/OpenSim.Server.Handlers.dll:GridServiceConnector"
GridInfoServerInConnector = "8002/OpenSim.Server.Handlers.dll:GridInfoServerInConnector"
AuthenticationServiceConnector = "8003/OpenSim.Server.Handlers.dll:AuthenticationServiceConnector"
OpenIdServerConnector = "8002/OpenSim.Server.Handlers.dll:OpenIdServerConnector"
AvatarServiceConnector = "8003/OpenSim.Server.Handlers.dll:AvatarServiceConnector"
LLLoginServiceInConnector = "8002/OpenSim.Server.Handlers.dll:LLLoginServiceInConnector"
PresenceServiceConnector = "8003/OpenSim.Server.Handlers.dll:PresenceServiceConnector"
UserAccountServiceConnector = "8003/OpenSim.Server.Handlers.dll:UserAccountServiceConnector"
GridUserServiceConnector = "8003/OpenSim.Server.Handlers.dll:GridUserServiceConnector"
FriendsServiceConnector = "8003/OpenSim.Server.Handlers.dll:FriendsServiceConnector"
MapAddServiceConnector = "8003/OpenSim.Server.Handlers.dll:MapAddServiceConnector"
MapGetServiceConnector = "8002/OpenSim.Server.Handlers.dll:MapGetServiceConnector"

Here all the public services (those where the viewer connects directly to the service) are served on port 8002, with internal services on 8003. So you need to make sure that the viewer can access port 8002 over TCP but you do not want to expose port 8003. Only simulators need to be able to connect to port 8003.

Connecting to a grid installation

Your client startup line will look something like


The loginuri needs to be the address to the login service. In standalone mode, this was the same address as the region simulator and the port was 9000 by default. However, in grid mode it will be the address to login service hosted on the ROBUST instance. In this case, the address will be The port number of 8002 is the traditional one for the grid login service and is the default in Robust.ini.example.

If the login is successful, you will see log lines on the ROBUST console (for the login itself) and then log lines on the region simulator console (as the login process tells the simulator to expect the avatar, tells the viewer the address of the region simulator and then when the viewer starts talking to the simulator directly).

Running multiple ROBUST service instances

This is a tricky issue and contrary to past allegations, opensim is not well prepared for this kind of microservices concepts.
You can split some services by different machines, if they have no interdependencies. For example current XBakes can run anywhere
Running several instances of same service is a invite to fail.
Some services do assume they are the only instance, like current PresenceService, GriduserService, etc, and even do own caching to reduce load on the database engine, and that cache cannot be syncronized across instances
Most will only service http in paralell, placing the same, and most of the load, on the same database engine. So unless that database service is a distributed system, doing proper local caching and synchronization with a master database, the gains of having multiple instances is not that large, if any if if not a total fail

Another important thing to note is that currently several services need to read data from the configuration of other services. For example Gridservice needs to read data from its section, GridService, and sections LoginService, Hypergrid and GridInfoService. So the ini file for the robust instance running it needs to have those sections, and of course updated.

If you are operating a grid, then you can run different services (e.g. asset, inventory) in different ROBUST instances, in order to spread the load. To do this, you will need to edit the ServiceConnectors parameter in the [Startup] section of Robust.ini (or Robust.HG.ini if you're running Hypergrid). The default ServiceConnectors parameter looks something like this

AssetServiceConnector = "8003/OpenSim.Server.Handlers.dll:AssetServiceConnector"
InventoryInConnector = "8003/OpenSim.Server.Handlers.dll:XInventoryInConnector"
GridServiceConnector = "8003/OpenSim.Server.Handlers.dll:GridServiceConnector"
GridInfoServerInConnector = "8002/OpenSim.Server.Handlers.dll:GridInfoServerInConnector"
AuthenticationServiceConnector = "8003/OpenSim.Server.Handlers.dll:AuthenticationServiceConnector"
OpenIdServerConnector = "8002/OpenSim.Server.Handlers.dll:OpenIdServerConnector"
AvatarServiceConnector = "8003/OpenSim.Server.Handlers.dll:AvatarServiceConnector"
LLLoginServiceInConnector = "8002/OpenSim.Server.Handlers.dll:LLLoginServiceInConnector"
PresenceServiceConnector = "8003/OpenSim.Server.Handlers.dll:PresenceServiceConnector"
UserAccountServiceConnector = "8003/OpenSim.Server.Handlers.dll:UserAccountServiceConnector"
GridUserServiceConnector = "8003/OpenSim.Server.Handlers.dll:GridUserServiceConnector"
FriendsServiceConnector = "8003/OpenSim.Server.Handlers.dll:FriendsServiceConnector"
MapAddServiceConnector = "8003/OpenSim.Server.Handlers.dll:MapAddServiceConnector"
MapGetServiceConnector = "8002/OpenSim.Server.Handlers.dll:MapGetServiceConnector"

Each entry has the form


For instance, the first entry above


says to start an AssetServiceConnector (and hence an asset service) from the OpenSim.Server.Handlers.dll and to server that from port 8003.

By default, Robust.exe loads a configuration file with the same name but with .ini appended instead of .exe. So Robust.exe will look for an inifile called Robust.ini. You can change this by giving the parameter on the commandline. For instance, to start Robust with HG parameters, one would use

Robust.exe -inifile=Robust.HG.ini

So if you wanted to run every connector apart from assets in one instance of ROBUST and the asset connector in another instance, you would have two ini files. One could remain Robust.ini and have

InventoryInConnector = "8003/OpenSim.Server.Handlers.dll:XInventoryInConnector"
GridServiceConnector = "8003/OpenSim.Server.Handlers.dll:GridServiceConnector"
GridInfoServerInConnector = "8002/OpenSim.Server.Handlers.dll:GridInfoServerInConnector"
AuthenticationServiceConnector = "8003/OpenSim.Server.Handlers.dll:AuthenticationServiceConnector"
OpenIdServerConnector = "8002/OpenSim.Server.Handlers.dll:OpenIdServerConnector"
AvatarServiceConnector = "8003/OpenSim.Server.Handlers.dll:AvatarServiceConnector"
LLLoginServiceInConnector = "8002/OpenSim.Server.Handlers.dll:LLLoginServiceInConnector"
PresenceServiceConnector = "8003/OpenSim.Server.Handlers.dll:PresenceServiceConnector"
UserAccountServiceConnector = "8003/OpenSim.Server.Handlers.dll:UserAccountServiceConnector"
GridUserServiceConnector = "8003/OpenSim.Server.Handlers.dll:GridUserServiceConnector"
FriendsServiceConnector = "8003/OpenSim.Server.Handlers.dll:FriendsServiceConnector"
MapAddServiceConnector = "8003/OpenSim.Server.Handlers.dll:MapAddServiceConnector"
MapGetServiceConnector = "8002/OpenSim.Server.Handlers.dll:MapGetServiceConnector"

The other could be called Robust.Assets.ini and have

AssetServiceConnector = "8004/OpenSim.Server.Handlers.dll:AssetServiceConnector"

Note that this is using port 8004 instead of port 8003. This is necessary since only one executable can use each port at a time. You will need to make sure your simulator configuration files use port 8004 for the asset service as well.

You will also need to change the default network port to 8004 for this second copy of Robust.exe

   port = 8004

Once you've created the two ROBUST configuration files (Robust.ini containing all services apart from asset and Robust.Assets.ini containing only the asset service), then you could start the first Robust.exe as usual.


This will load Robust.ini, as we haven't specified a Robust.ini. Also, the logfile it will use will be Robust.log as we haven't manually specified one.

The second ROBUST instance we would start with

Robust.exe -inifile=Robust.Assets.ini -logfile=Robust.Assets.log

The -inifile switch tells the second Robust instance to load it's configuration from Robust.Assets.ini rather than Robust.ini. The -logfile switch tells Robust.exe to use Robust.Assets.log as its logfile rather than the default Robust.log. If you don't specify this switch then you may see errors on the console about a locked log file.

At this point you should have two running Robust.exe instances.

If you put the ROBUST instances on different machines then don't forget to change the relevant service URIs in each simulator to match.

Since OpenSimulator services are stateless (e.g. every request is unconnected with other requests as long as they affect the same persistent data where necessary), you can also load balance by starting more than one ROBUST instance with a copy of the same service (e.g. multiple asset services using the same database). Requests would be round-robined between the service copies using an HTTP reverse proxy implementation (e.g. nginx). See Performance#Services for more details.


Useful discussion about separating Robust instances

Attaching your sim to someone else's grid

  • Make sure you understand, agree and will enforce that grid Terms of Service
  • Follow the instructions of that grid owner!

To set up the region server (i.e., OpenSim.exe) to connect to an external grid, follow the Configuration#Step 2: Configure an OpenSim.exe to use the ROBUST services instructions above.

The grid will have already provided with the required services. In step 2 you will need to use the provided URLs for their services.

In your bin/Regions.ini file (or other region config file) you will also need to set the grid co-ordinates to your regions provided from the grid operator. See Configuring Regions for more information.

Running an OpenSimulator standalone or grid installation with Hypergrid enabled

Hypergrid is an emerging architecture supported by OpenSimulator that allows a user with an account on one standalone or grid to visit other Hypergrid-enabled standalones or grids, and for users from those grids to visit the home grid. This does not require the two installations to share a central set of data services (assets, inventory, etc.). Please see Installing and Running Hypergrid for more details.

Further notes


See Troubleshooting

Running OpenSimulator in 32 bit in Windows 64bit

This is no longer possible since because newer versions of dotnet do not support 32Bit on windows.

Windows 64Bit can run several instances of OpenSim in 32Bit mode, allowing each to use up to about 2GB of total physical ram.

This is almost the total memory available on 32Bit versions of Windows, for all the programs (around 3GB)

In 32Bit mode, the simulator uses less memory and may be a bit faster, so unless you have very large regions, you can ran it in 32Bit mode, just run:

OpenSim32.exe instead of OpenSim.exe

You can also run Robust in 32Bit mode:

Robust32.exe in place of Robust.exe

Linux 64Bit only runs the simulator in 64Bit mode

Increasing the stack reserve level when using OpenDynamicsEngine (old ODE and ubODE) on Linux or other Unix variants

Increase your stack reserve level with the following command; ulimit -s 262144 Or, run the to start up OpenSimulator.

dotnet runtime configuration (version and above)

Files Robust.runtimeconfig.json, OpenSim.runtimeconfig.json and other *.runtimeconfig.json on folder bin/ define several settings the the dotnet runtime will use for the respective application.
You should not change those files, unless you do understand the impact of such changes.

one case you should review is the line

   "System.GC.HighMemoryPercent": 50,

dotnet runtime assumes that a application runs alone on the machine, so it can use all its memory. Even in workstation mode ( server is a lot worse), GC will only try really harder to release memory if it is using more than 90% of total machine physical memory, on that application alone.

The line above changes that to 50%. On small regions, specially if running several, you may want to reduce it even more, for example:

   "System.GC.HighMemoryPercent": 5,

will change it to try to free memory harder above 5% of total memory use, i.e. at approximately 1.6GB on a 32GB machine, etc.
the value should be between 1 and 90 (dotnet default). If the line is removed the dotnet default is used
If you set the value too low, the CPU load (and so lag) will increase.

Changes to this files maybe lost on compile!

Region and robust console command "show stats" now lists this threshold as GCHMthreshold

see garbage collector high memory percent for more information.


Some operation systems or distributions run their own firewall by default. If you can't access to OpenSimulator from remote client, you'll need to check their settings. See Firewall Settings for details.

Legacy Configuration Information

These are some pages containing some legacy configuration information of unknown accuracy.

OpenSim 0.6.6 legacy configuration information

Additional Optional Configuration Tasks

Further configure OpenSimulator

If you've looked through OpenSim.ini.example or any other of the config files, you'll see that there's a very large number of configurable parameters spread across multiple files. See Configuring Simulator Parameters for more details about the configuration infrastructure and how settings in identically named sections (e.g. [XEngine]) are merged by OpenSimulator on loading.

Set up a second region to run on the same simulator

See Configuring Regions.

Run Multiple Standalone Instances of OpenSimulator on the Same Server

For each subsequent instance of OpenSim, change the 'http_listener_port' in OpenSim.ini to the value excluding 9000, and 'InternalPort' in Regions.ini to the value excluding 9000. Also, make sure your regions are using different ports, as explained in Configuring Regions.

Load region content

You can load content onto regions by using the load oar command. To load individual OAR files into each region, use the 'change region [regionname]' command and then 'load oar [oar-location]'.

OpenSim.exe command line options

OpenSim.exe has command line options which allow you to perform actions such as reading configuration files from a different directory. See OpenSim.exe Command Line Options for more details.

Script engine

OpenSimulator supports multiple script engines. See ScriptEngines for details. If you don't know what this means then the default script engine will be fine. In fact, recent versions of OpenSimulator only ship with one script engine, the XEngine.

Permissions Configuration

OpenSimulator has a quite elaborate set of permissions. See Permissions (Server) for details. By default, permissions are active on region simulators.


By default, OpenSimulator logs information to a file called OpenSim.log in the bin directory. See Logging for details on how to further configure this if required.

FSAsset Service

By default the OpenSimulator asset service will store assets in the robust database. If you expect your asset data to grow larger than 50Gb you should consider changing to the FSAssets Service. (FSAssets is a new service and is currently only available in the latest development branch)

Set up other optional modules

Configuration of Web Server and Pages

OpenSimulator contains a web server that can serve up a variety of pages. Some which come from external files and some are generated internally.

Where to go from here

  • Upgrading from an old OpenSimulator version to a newer one.