A startup process failure on ArcGIS for Server returns the following error message in the ldap.log file:
"ERROR<39170> - Auto-Upgrade - conn=-1 op=-1 msgId=-1 - Configuration error Phase 1/2 of the data upgrade has failed. Please refer to the error log or output for more information. Server not running!! Failed to start ns-slapd process."
The error is caused by a missing dse.ldif file. This file is a Directory Server configuration file that is read once during startup. The file can go missing at times due to an improper shutdown of the server.