Job fails to start due to timeout
Challenge
In Veeam Backup & Replication, if more than 100 jobs are running simultaneously, and the user attempts to start more jobs, they may fail to start with the following error message:
Error Job <JobName> cannot be started. SessionId: <UUID>, Timeout: [361 sec]
A Veeam Agent for Microsoft Windows backup job may fail with:
Managed session <UUID> has failed
In the Veeam Agent for Microsoft Windows service logs (Svc.VeeamEndpointBackup.log) following errors are found:
Error Job <JobName> cannot be started. SessionId: <UUID>, Timeout: [361 sec] Error Job [Infrastructure update] has failed to start. Timeout expired (6 minutes). SessionId: <UUID>
The following event is found in the System event logs:
Log Name: System Source: Win32k Event ID: 243 Task Category: None Level: Warning Keywords: Classic User: N/A Computer: Description: A desktop heap allocation failed.
Cause
By default, Veeam services are run as the LocalSystem account. As a result, all processes are started under NT AUTHORITY\SYSTEM context. If the Windows OS is running out of Desktop Heap memory, new processes can't be started.
Solution
The Desktop Heap size must be increased via a registry modification.
Because this change will affect the desktop heap of all services (also known as non-interactive window stations), do not make the new value larger than necessary.
Run regedit and navigate to
HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems
Find string named “Windows”
Edit the Value data to change the third “SharedSection” value only. Do not modify any other values.
Press OK Reboot the machine