This chapter contains information on recovering from system and media failures. The first part of this chapter discusses how to restart the application server if the system ends abnormally. The second part, Resolving CICS In-Doubt Logical Units of Work, discusses how to resolve logical units of work that have not been committed or rolled back when you restart the application server. CICS in-doubt logical units of work can only occur in a DB2 Server for VM VSE guest sharing environment. The final part of this chapter discusses what to do if you have a DASD failure.