Hi @PLP-Lack , 

you haven’t specified if linux system are phisical or virtual machine but error seems to be a failure in connection to the OS. 

Please check list of used ports needed from Veeam B&R and Linux machine. 

Hi,
one system is CentOS 7 and the other AlmaLinux 8.6.

How can check the ports Veeam B&R needs?

Hi @PLP-Lack , here are port requirements for Veeam. To further test, you could disable app aware processing & attempt another backup try; this will check if there's something wrong permissions wise. 

Do you actually need guest file indexing? With this feature you can search for files via the enterprise manager. But if you don't plan to use it, then just disable the option in your job under guest processing.

I would suggest the same thing here after checking the ports.

For a quick check, you can use the “Test Now” button in the “Guest Processing” step of the Backup Job wizard. For Linux VMs, it also verifies that the machine has the required packages (openssh, gzip, tar) for indexing.

Thank your for your help, i had a problem with the user i used for the indexing.

Glad to hear you got it resolved. 

Great to hear it was something simple like a user that solved the issue.