Limiting RAM usage by the Cloud Backup agent

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Updated at July 9, 2026

For faster data backup and recovery, the Cloud Backup agent can consume significant amounts of RAM of the backed up resource, i.e., virtual machine or BareMetal server. The agent can even use up all the available RAM, which in some cases may disrupt the resource's other services and make it impossible to complete the backup or recovery process.

To prevent such issues, you can limit the amount of data the agent caches in RAM.

Note

Limiting the Cloud Backup agent's use of RAM may slow down the backup and recovery operations.

To limit the use of RAM by the agent:

Linux

Windows

Connect to the VM or BareMetal server over SSH.
Stop the backup agent system process by running the following command in the terminal:
```
sudo service acronis_mms stop
```
Open the agent configuration file:
```
sudo nano /usr/lib/Acronis/system_libs/config
```
If the configuration file does not exist, it will be created.
Add the following line to the opened configuration file:
```
export A3_CACHE_SIZE=<RAM_limit>
```
Where the A3_CACHE_SIZE variable sets the RAM limit for the agent. For example, for a 2 GB limit, specify A3_CACHE_SIZE=2G or A3_CACHE_SIZE=2048M.
Save the changes and close the configuration file.
Restart the backup agent system process:
```
sudo systemctl restart acronis_mms
```

Connect to the VM via RDP or to the BareMetal server using the KVM console.
Run PowerShell as an administrator.
In the PowerShell terminal, run this command:
```
setx /M A3_CACHE_SIZE <RAM_limit>
```
Where the A3_CACHE_SIZE variable sets the RAM limit for the agent. For example, for a 2 GB limit, specify A3_CACHE_SIZE 2G or A3_CACHE_SIZE 2048M.

Result:
```
SUCCESS: Specified value was saved.
```

Restart Acronis Managed Machine Service:

Stop Acronis Managed Machine Service:

net stop MMS

Result:

The Acronis Managed Machine Service service is stopping..
The Acronis Managed Machine Service service was stopped successfully.

Restart Acronis Managed Machine Service:

net start MMS

Result:

The Acronis Managed Machine Service service is starting.
The Acronis Managed Machine Service service was started successfully.

Limiting RAM usage by the Cloud Backup agent

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