Symptoms
Provisioning Panel_6_1" for APS application Cloud Infrastructure task failed with Server-side erorr.
The following could be observed in installer_output.log in container:
PHP Warning: proc_open(): fork failed - Cannot allocate memory in /usr/local/psa/admin/plib/common_func.php on line 213
PHP Warning: proc_open(): fork failed - Cannot allocate memory in /usr/local/psa/admin/plib/common_func.php on line 489
Cause
Not enough memory for Plesk installation. The documentation issue CCU-20155 has been submitted to R&D team to note this behavior in documentation.
Resolution
This behavioris described in Plesk KB article