When an agent is installed, a new entry is created in Acronis software and the machine is displayed in the Backup management console. 

When the Agent is reinstalled, a second entry might appear for the same machine and new backup archives for this machine will be created once old backup plans are applied. 

To prevent these duplicates from appearing, leave Remove the logs and configuration settings (Windows) or Clean up all product traces (Linux) cleared.


This KB describe way to register machine in Acronis Management Server and to continue backing up to old archives.


Every time an Agent is installed, the machine receives unique parameters - MMSCurrentMachineID and InstanceID. These parameters are stored in the HKLM\Software\Acronis\BackupAndRecovery\Settings\MachineManager registry key.

In order to preserve the original MMSCurrentMachineID and InstanceID when reinstalling the Agent proceed according to the steps below:

1. Record down the original MMSCurrentMachineID and InstanceID:

  • Either in Windows Registry on the machine
  • Or in the browser address bar while selecting the machine in backup management console. 

            GUID between "phm." and "%40" is InstanceID, after "%40" is MMSCurrentMachineID

            example https://backup.exabytes.my/bc/#login=albert-exabytes&m=Resources&s=1&key=all&id=phm.19A64B2A-3B14-4A1B-888E-D0B2C034BFB6%408F08DDA9-3990-46F7-8107-490ACAB6D5D8.disks

2. Make sure that machine is not present in the Backup management console. If it presents, delete it.

3. If the Agent is still installed on the machine, proceed to next step. If not, it is necessary to install the Agent without registering machine in the Management Server:

- Download the full installation file from the Backup management console.
- Run it and choose Create .msi and .mst files for unattended installation. Select components you need to install.
- Once the files are extracted, start command prompt as Administrator, navigate to the folder you have extracted installation file to (use the cd command) and start installation using the following command:

msiexec /i BackupClient64.msi /qb /l*v install.log ADDLOCAL=MmsMspComponents,BackupAndRecoveryAgent,TrayMonitor, REBOOT=ReallySuppress ENABLE_COMMON_ERRORS=1 MMS_MUST_BE_REGISTERED=0 CREATE_NEW_ACCOUNT=1 ACEP_AGREEMENT=1

The command above installs only Agent for Windows and Tray monitor. To install additional components, add the following strings under "ADDLOCAL=<component>"
where <component> is ArsAgentFeature for the Agent for SQL; HyperVAgent for the Agent for Hyper-V; ArxAgentFeature for the Agent for Exchange.


If the Managed machine service needs to be run by an existing user the installation string should be as follows:

msiexec /i BackupClient64.msi /qb /l*v install.log ADDLOCAL=MmsMspComponents,BackupAndRecoveryAgent,TrayMonitor, REBOOT=ReallySuppress ENABLE_COMMON_ERRORS=1 MMS_MUST_BE_REGISTERED=0 MMS_SERVICE_USERNAME=<username> MMS_SERVICE_PASSWORD=<password> ACEP_AGREEMENT=1


4. Change values of MMSCurrentMachineID and InstanceID to the original ones, once the Agent is installed:


Windows: start Windows registry editor (Start -> Search -> regedit.exe) and navigate to the following key: HKLM\Software\Acronis\BackupAndRecovery\Settings\MachineManager


Linux: open /etc/Acronis/BackupAndRecovery.config and modify these values:
     <value name="InstanceID" type="TString">
                                "<insert_value_noted_in_step1>"
                        </value>
                        <value name="MMSCurrentMachineID" type="TString">
                                "<insert_value_noted_in_step1>"
                        </value>

Mac: open /Library/Application Support/Acronis/Registry/BackupAndRecovery.config and modify these values:
     <value name="InstanceID" type="TString">
                                "<insert_value_noted_in_step1>"
                        </value>
                        <value name="MMSCurrentMachineID" type="TString">
                                "<insert_value_noted_in_step1>"
                        </value>


5. Register machine manually according to this KB article.

6. Log in to the Backup management console and check whether the machine has appeared. Apply original backup plan(s) to the machine.


Additional information

This method can be used to preserve original file-level backup plans in case of machine replacement and Agent reinstallation on the new machine:

  1. You have been creating file-level backups with Acronis backup software.
  2. You are about to decommission the machine, replace the machine with a new one, reinstall the operating system, or restore your machine from an existing backup you have created with another vendor's backup software.
  3. You want to restore files to the new machine and continue backing up.

In this case you need to restore from your file-level backups, and then proceed as described in the Solution part above.