--- a/src/hotspot/share/memory/filemap.cpp	Tue Nov 27 13:39:57 2018 -0500
+++ b/src/hotspot/share/memory/filemap.cpp	Tue Nov 27 17:53:17 2018 -0500
@@ -683,7 +683,10 @@
   int arr_len = heap_mem == NULL ? 0 : heap_mem->length();
   if(arr_len > max_num_regions) {
     fail_stop("Unable to write archive heap memory regions: "
-              "number of memory regions exceeds maximum due to fragmentation");
+              "number of memory regions exceeds maximum due to fragmentation."
+              "Please increase java heap size "
+              "(current MaxHeapSize is " SIZE_FORMAT ", InitialHeapSize is " SIZE_FORMAT ").",
+              MaxHeapSize, InitialHeapSize);
   }
 
   size_t total_size = 0;

--- a/test/hotspot/jtreg/runtime/appcds/LotsOfClasses.java	Tue Nov 27 13:39:57 2018 -0500
+++ b/test/hotspot/jtreg/runtime/appcds/LotsOfClasses.java	Tue Nov 27 17:53:17 2018 -0500
@@ -57,9 +57,16 @@
         opts.addSuffix("--add-modules");
         opts.addSuffix("ALL-SYSTEM");
         opts.addSuffix("-Xlog:hashtables");
+        opts.addSuffix("-Xms500m");
+        opts.addSuffix("-Xmx500m");
 
         OutputAnalyzer out = CDSTestUtils.createArchive(opts);
-        CDSTestUtils.checkDump(out);
+        try {
+            CDSTestUtils.checkDump(out);
+        } catch (java.lang.RuntimeException re) {
+            out.shouldContain(
+                "number of memory regions exceeds maximum due to fragmentation");
+        }
     }
 
     static void findAllClasses(ArrayList<String> list) throws Throwable {