https://blogs.oracle.com/EMMAA/entry/java_heap_size_settings_for
Oracle Enterprise Manager 12.1.0.4 Configuration Best Practices (文档 ID 1929586.1)
[oracle@szxcld001 bin]$ 
[oracle@szxcld001 bin]$ emctl list properties -module emoms
EM Configuration issue. /data01/app/oracle/product/11.2.0.4/db_1/szxcld001.hwc.com_em12c not found. 
[oracle@szxcld001 bin]$ ./emctl list properties -module emoms  
Oracle Enterprise Manager Cloud Control 12c Release 4  
Copyright (c) 1996, 2014 Oracle Corporation.  All rights reserved.
SYSMAN password: 
Property Details
    Management Server : szxcld001.hwc.com:4889_Management_Service
        Module = EMOMS
            JAVA_EM_ARGS=
            JAVA_EM_MEM_ARGS=
            JBO_LAZY_LOAD=true
            JBO_MAX_CURSORS=5
            JBO_MAX_POOL_SIZE=50
            JBO_MIN_POOL_SIZE=1
            JBO_POOL_TTL=-1
            JBO_RECYC_THRESHOLD=50
            OMS_HEAP_MAX=4096M
            OMS_HEAP_MIN=4096M
            OMS_PERMGEN_MAX=1024M
            OMS_PERMGEN_MIN=1024M
            emConfigMBeanPort=0
            is_admin_server=true
            max_target_pooled_connections=4
            oracle.sysman.asr.diag_retry_count=3
            oracle.sysman.asr.diag_retry_freq=15
            oracle.sysman.asr.diagcoll_incident_count_interval=1
            oracle.sysman.asr.diagcoll_incident_count_maximum=1
            oracle.sysman.asr.dts_base_url=https://transport.oracle.com/v1
.... 
            oracle.sysman.ssa.logon.cloud_tenant_alt_text=null
            oracle.sysman.ssa.logon.disclaimer_text=null
            oracle.sysman.ssa.logon.show_cloud_provider_brand=false
            oracle.sysman.ssa.logon.show_cloud_tenant_brand=false
            oracle.sysman.ssa.logon.show_disclaimer_text=false
            oracle.sysman.ssa.logon.show_em_branding_text=true
            oracle.sysman.ssa.logon.ssa_oms=false
            use_pooled_target_connections=false
[oracle@szxcld001 bin]$ 

本文转自ITPUB博客tolywang的博客，原文链接：EM 12c 修改EMGC_OMS1的 java heap size (JVM大小) - 1，如需转载请自行联系原博主。