Cloud server with Matrix

Last update: July 21 2026

Matrix is an open protocol for decentralized and secure messaging. A cloud server with Matrix is a software server that provides communication and data synchronization in the Matrix network.

In Selectel, a cloud server with Matrix includes:

• Synapse — a server-side implementation of the Matrix protocol;
• Element Web — a web interface for the Matrix network that allows you to interact with the Matrix network via a web browser without the need to install additional software;
• Coturn — open-source software that helps establish direct audio, video, and data connections between devices on the internet.

You can create a cloud server with a pre-installed Matrix application. In Russia, the application runs on a cloud server with a pre-configured SelectOS 1 64-bit operating system. In other countries — Ubuntu 22.04.

Before creating a cloud server with an application, read the software license agreements included in the image.

Minimum resource requirements

Number of vCPUs	2
RAM	4 GB
Boot volume	20 GB

Create a cloud server with Matrix

For Matrix to work, the cloud server must be accessible from the internet. To do this, when creating the server, you must create a private network and attach a public floating IP address. To configure Matrix, you must specify user data — custom operating system configuration parameters — when creating the server.

After the server with Matrix is created, a free TLS certificate from Let’s Encrypt® will be automatically issued for the domain you specify. To issue the certificate, add an A record for the domain and specify the server's public floating IP address as the record value. You can add the domain to Selectel DNS Hosting (actual).

1. Create a public floating IP address.

2. Add an A record for the domain.

3. Create a cloud server with Matrix.

1. Create a public floating IP address

Create a public floating IP address so that the cloud server with Matrix is accessible from the internet.

Use the Create a public floating IP address section of the Public Floating IP addresses guide.

2. Add an A record for the domain

Add a resource record to access Matrix by domain.

Specify:

• resource record type — A;
• record value — the public floating IP address you created in step 1.

3. Create a server with Matrix

1. In the Control panel, on the top menu, click Products and select Cloud Servers.

2. Click Create server.

3. Fill in the blocks:

   • Name and placement;
   • Source;
   • Configuration;
   • Volumes;
   • Internet;
   • Private network;
   • Security;
   • Access;
   • Additional settings.

4. Check the cloud server price.

5. Click Create.

Name and placement

1. Enter the server name. It will be set as the hostname in the operating system.

2. Select a location where the server will be created. The list of available server configurations and resource costs depends on the location. You cannot change the location after the server is created.

Source

1. Open the Applications tab.

2. Select Cloud Matrix.

3. Optional: if you need a different current or archived application version, in the Version field, select the required version.

Configuration

Select a configuration from 2 vCPU, RAM starting from 4 GB and a boot disk size starting from 20 GB. For all lines other than Shared and Dedicated, two types of server configurations are available:

• fixed configurations — ranges with different technical specifications where the resource ratio is fixed;
• custom configurations — configurations where you can specify any resource ratio.

Configurations use different processors depending on the line and pool segment. You can adjust the selected configuration. After the server is created, you can change the configuration.

Fixed configuration

1. Open the tab with the range.

2. Click Fixed.

3. Optional: you can adjust the configuration, if you are creating a server in a multi-AZ pool ru-6 segment or ru-3b, ru-7a, and ru-7b pool segments:

   3.1. Expand the block with the configuration settings description.

   3.2. Optional: select the processor manufacturer. Choosing the manufacturer is not available in all pools.

   3.3. Optional: if you do not want physical processor cores to be reserved for the cloud server vCPU, clear the Dedicated Cores checkbox. For more details, see the Dedicated Cores instruction.

   3.4. Optional: if you want to disable Hyper-Threading for a server with dedicated cores, uncheck the Hyper-Threading (SMT) box.

   3.5. Optional: if you are creating a server with dedicated cores and want to place a multiprocessor server on one NUMA node, select the Mandatory placement on a single NUMA node checkbox. A server with 4 vCPU or more can be placed on a single NUMA node. If the cloud server resources cannot be placed on one node, it will not be created. For more details, see the Placement on a single NUMA node subsection of the Dedicated Cores instruction.

4. Select a configuration.

5. If both local and network volumes are available in the selected configuration, select the volume to be used as the boot disk:

   • local disk — check the Local SSD NVMe disk box. A server with a local disk can only be created from images and applications;
   • network volume — do not check the Local SSD NVMe disk box.

   The amount of RAM allocated to the server may be less than specified in the configuration — the operating system kernel reserves a portion of RAM depending on the kernel version and distribution. You can check the allocated amount on the server using the sudo dmesg | grep Memory command.

Custom configuration

1. Open the tab with the range.

2. Click Custom.

3. Optional: you can adjust the configuration, if you are creating a server in a multi-AZ pool ru-6 segment or ru-3b, ru-7a, and ru-7b pool segments:

   3.1. Expand the block with the configuration settings description.

   3.2. Optional: select the processor manufacturer. Choosing the manufacturer is not available in all pools.

   3.3. Optional: if you do not want physical processor cores to be reserved for the cloud server vCPU, clear the Dedicated Cores checkbox. For more details, see the Dedicated Cores instruction.

   3.4. Optional: if you want to disable Hyper-Threading for a cloud server with dedicated cores, uncheck the Hyper-Threading (SMT) box.

   3.5. Optional: if you are creating a cloud server with dedicated cores and want to place a multiprocessor server on one NUMA node, select the Mandatory placement on a single NUMA node checkbox. A cloud server with 4 vCPU or more can be placed on a single NUMA node. If the cloud server resources cannot be placed on one node, it will not be created. For more details, see the Placement on a single NUMA node subsection of the Dedicated Cores instruction.

4. Specify the number of vCPUs.

5. Specify the RAM size.

6. If you need to add GPUs to the server, click Add GPU, select the GPU type, and specify the number of GPUs. The selected line will change to the GPU line. If you selected an image without GPU optimization in the Source block and the Auto-select GPU image toggle is turned on, the selected image will automatically change to a GPU-optimized image.

7. If both local and network volumes are available in the selected configuration, select the volume to be used as the boot disk:

   • local disk — check the Local SSD NVMe disk box. A server with a local disk can only be created from images and applications;
   • network volume — do not check the Local SSD NVMe disk box.

   The amount of RAM allocated to the server may be less than specified in the configuration — the operating system kernel reserves a portion of RAM depending on the kernel version and distribution. You can check the allocated amount on the server using the sudo dmesg | grep Memory command.

Volumes

1. If you did not check the Local SSD NVMe disk checkbox when setting up the configuration, the first specified network volume will be used as the server boot disk. To configure it:

   1.1. Select the type of network boot disk.

   1.2. Specify the size of the network boot disk in GB or TB. Observe the maximum size limits for network volumes.

   1.3. If you selected the Universal v2 or Fast SSD v2 disk type, specify the total number of read and write operations in IOPS. After the volume is created, you can change the IOPS value — reduce or increase it. The number of IOPS changes is unlimited.

2. Optional: add an additional network volume server :

   2.1. Click Add.

   2.2. Select the type of network volume.

   2.3. Specify the size of the network disk in GB or TB. Observe the maximum size limits for network volumes.

   2.4. If you chose the Universal v2 or SSD Fast v2 volume type, specify the total IOPS (read and write operations). After the volume is created you can change the IOPS — decrease or increase them. There is no limit to the number of IOPS changes.

   After creating the server, you will be able to attach new additional volumes.

Internet

Set up public access to the server.

The cloud server will be added to a private subnet connected to a cloud router with 1:1 NAT and internet access. Internet connectivity will be managed through the cloud router. The server will be accessible from the internet via a public floating IP address.

1. In the Connection from the internet field, select the Public floating IP address access type.

2. Select the public floating IP address that you created in step 1.

Private network

A cloud server can be added to an existing or new private subnet.

Existing private subnet

1. In the Subnet field, select a private subnet.

2. Optional: in the IP address field, change the default IP address.

3. In the Router field, select an existing router or create a new one.

   If the router is not connected to the internet, it will be automatically connected to the internet after the server is created.

New private subnet

1. In the Subnet field, select New private subnet.

2. In the Network field, select an existing network or create a new one.

3. Optional: change the subnet CIDR.

4. Optional: in the IP address field, change the default IP address.

5. In the Router field, select an existing router or create a new one.

   If the router is not connected to the internet, it will be automatically connected to the internet after the server is created.

Security

Select security groups to filter traffic on the server ports. Without security groups, traffic will be blocked. If the block is missing, traffic filtering (port security) is disabled in the server network. With traffic filtering disabled, all traffic will be allowed.

Access

1. Place an SSH key for the project on the server for secure connection:

   1.1. If an SSH key for the project is not added to the cloud platform, click Add SSH key, enter the key name, paste the public key in OpenSSH format, and click Add.

   1.2. If an SSH key for the project has been added to the cloud platform, select an existing key in the SSH key field. The SSH key is only available in the pool where it is located.

2. Optional: in the Password for root field:

   2.1. Copy the password for the root user — the user with unrestricted privileges for all system actions.

   2.2. Save the password in a secure place and do not share it in plain text.

Additional settings

1. Optional: if you plan to create multiple servers and want to increase infrastructure fault tolerance, add the server to a placement group:

   1.1. To create a new group, in the Placement group field, click Create.

   1.2. Select New group and enter the group name.

   1.3. Select a placement policy on different hosts:

   • preferred — soft-anti-affinity. The system will try to host the servers on different hosts. If there is no suitable host when creating the server, it will be created on the same host;
   • mandatory — anti-affinity. Servers in the group must be located on different hosts. If there is no suitable host when creating the server, the server will not be created.

   1.4. Once the group is created, in the Placement group field, select the placement group.

2. Optional: to add additional information or filter servers in the list, add server tags. OS and configuration tags are added automatically. To add a new tag, in the Tags field, enter the tag.

3. To add a script that will be executed using the cloud-init agent at the first operating system startup, in the Automation block in the User data field:

   • open the Text tab and paste the script as text;
   • or open the File tab and upload the file with the script.

#cloud-config
 
write_files:
- path: "/opt/gomplate/values/user-values.yml"
  permissions: "0644"
  content: |
    domain: "<example.com>"
    adminEmail: "<root@example.com>"

Specify:

• <example.com> — the domain for accessing the Matrix web interface that you added in step 2;
• <root@example.com> — Matrix administrator email for issuing a Let’s Encrypt® certificate.

Create a Matrix user

1. Connect to the cloud server via SSH.

   After connecting to the cloud server, a message with available actions will appear. Example of the output:

   1) Управление пользователями
   2) Обновление Synapse / Element-Web
   0) Выход

2. Go to the user management menu; to do this, enter 1 and press Enter.

3. Create a user; to do this, enter 1 in the user management menu and press Enter.

4. Enter the username and press Enter.

5. Enter the user password and press Enter.

6. Make sure the user was created.

   6.1. Open the user list; to do this, enter 6 in the user management menu and press Enter.

   6.2. Make sure the list contains the username you entered in step 4.

   6.3. Return to the menu; to do this, enter 0 and press Enter.

7. Optional: make the user an administrator.

   7.1. Open administrator settings; to do this, enter 2 in the user management menu and press Enter.

   7.2. Enter the name of the user you want to make an administrator.