Hi,
I configure two hyper-v vm in one job, so I configured credentials for app aware processing for every individual of this two vm,
I have verified connectivity and credentials for each machine, but veeam ask me for Guest Os Credentials but credentials for first or second VM?
These are the default ones that will be applied to any server if you not define differently. You can use one of your credentials there.
If you then click on "Applications..." you can select specific servers and define specific credentials for them.
If you have for example selected a group by folder or tag, you can define for each group the Credentials, but can as well use the "Applications..." - "Add..." button to add specific servers and define credentials for them.
I guess that this page of our help center might be helpful, for example:
By default, Veeam Backup & Replication uses the same credentials for all VMs in the job. If some VM requires a different user account, click Credentials and enter custom credentials for the VM.
This table provides the list of required permissions for each application. One more thought to keep in mind regarding SQL is how do you need to process SQL transaction logs or do you need to backup SQL in copy only mode. This section should give you a better idea of possible scenarios.