LNMSHASHTBL is a system parameter that sets the size of the system logical name hash table. Logical names are hashed using a function of the name length and contents. The LNMSHASHTBL parameter determines the number of entries for shareable logical names. These names include all names from the system, group, and job logical name tables. The recommended setting allows one to four logical names per hash table entry. The default setting is usually adequate, unless your installation has a large number of groups, or many jobs are active simultaneously. In that case, an increase in the value of the next higher power of 2 might improve logical name translation performance. Note that the hashed values are rounded up to the nearest power of 2.
LNMSHASHTBL has the AUTOGEN, FEEDBACK, and GEN attributes.