From Virtual Entity of Relevant Acronyms (Version 1.9, June 2002):

SMS
     Service Management System
     
     

From Virtual Entity of Relevant Acronyms (Version 1.9, June 2002):

SMS
     Short Message Service (GSM, mobile-systems)
     
     

From Virtual Entity of Relevant Acronyms (Version 1.9, June 2002):

SMS
     Storage Management Services (Novell, Netware)
     
     

From Virtual Entity of Relevant Acronyms (Version 1.9, June 2002):

SMS
     System Management Server (MS)
     
     

From Virtual Entity of Relevant Acronyms (Version 1.9, June 2002):

SMS
     System-Managed Storage
     
     

From The Free On-line Dictionary of Computing (27 SEP 03):

SMS
     
        1. <messaging> Short Message Service.
     
        2. <storage> Storage Management Services.
     
        3. <operating system> System Management Server.
     
        (1999-05-02)