After running the Post Installation for ArcGIS Server, a summary log file is created. This log file is used to review how the ArcGIS Server environment was configured and to resolve any permission/rights issues after installation.
The log file name is ArcGISServerPostInstallLog.txt.
The log file is written to the %TEMP% directory defined for the Windows user account that installed ArcGIS Server.
The log file is written to /var/tmp.