Request servers Worker servers Other servers 6.3.3 VSMGUARD A listening request server receives a connection request from a client, establishes a  connection, and then accepts requests from that client. The following request servers are  available: The worker servers process API function requests. The following worker servers are defined  in the default installation: A fourth worker server, VSMGUARD, is also defined. VSMGUARD is a “guard” server that  helps provide better resiliency and error recovery. For more information, see 6.3.3,  “VSMGUARD” on page 169. The following severs also are available: The VSMGUARD worker server grants authority to all the other SMAPI servers that are  configured to access the SMAPI file space. Therefore, VSMGUARD must be made an  administrator of the VMSYS: file pool. This process is done by adding VSMGUARD to the list  of users that are authorized for ADMIN authority.  Note:  In the default environment, this process is done by updating the  VMSERVS DMSPARMS file on the VMSERVS 191 disk. VSMGUARD has an important role in the SMAPI environment. When you must recycle all  SMAPI user IDs, you do it by recycling VSMGUARD ( force  and  xautolog ) and it recycles all  the other SMAPI user IDs, saves the SMAPI segment, and defines the vSwitches that are  listed in the configuration file. GLYPH<SM590000> The LOHCOST server is used for caching the system directory contents that are required  to satisfy the various query APIs. It is also used to store and retrieve data that is used by  the metadata APIs. GLYPH<SM590000> The DTCSMAPI server is used by several of the SMAPI servers for communication and  workload balancing. GLYPH<SM590000> The PERSMAPI server is used for performance monitoring. GLYPH<SM590000> The VSMEVSRV server is used to listen for and then propagate VMEVENT and directory  updates. GLYPH<SM590000> The OPERATNS server is used to collect, format, and distribute ABEND memory dumps. Note:  For more information about SMAPI, see  The Systems Management Application  Programming for 6.4 , SC24-6327. Chapter 6. Securing a cloud in an IBM z/VM environment  169 GLYPH<SM590000> VSMREQIN GLYPH<SM590000> VSMREQI6 GLYPH<SM590000> VSMREQIU GLYPH<SM590000> VSMEVSRV GLYPH<SM590000> VSMWORK1 GLYPH<SM590000> VSMWORK2 GLYPH<SM590000> VSMWORK3