If the VM fails to map the shared string region, with -Xshared:auto it disables sharing and continues. There is an assertion failure in GC later on when it scans the "archived" region. The assertion failure was first discovered on Windows when I tried to enable the shared string support. The mapping of shared string region failed on Windows.

# To suppress the following error report, specify this argument
# after -XX: or in .hotspotrc:  SuppressErrorAt=/klass.inline.hpp:63
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/export/users/jiangli/jdk9/hotspot/src/share/vm/oops/klass.inline.hpp:63), pid=30067, tid=0x00007fffdcf17700
#  assert(!is_null(v)) failed: narrow klass value can never be zero
#
# JRE version: Java(TM) SE Runtime Environment (9.0) (build 1.9.0-internal-debug-jianzhou_2015_06_08_16_34-b00)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (1.9.0-internal-debug-jianzhou_2015_07_16_18_42-b00 mixed mode linux-amd64 compressed oops)
# Core dump will be written. Default location: Core dumps may be processed with "/usr/share/apport/apport %p %s %c" (or dumping to /export/users/jiangli/build-64/images/jdk/core.30067)
#
# An error report file with more information is saved as:
# /export/users/jiangli/build-64/images/jdk/hs_err_pid30067.log
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.java.com/bugreport/crash.jsp
#

#0  0x00007ffff7837445 in raise () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007ffff783abab in abort () from /lib/x86_64-linux-gnu/libc.so.6
#2  0x00007ffff66dfe3e in os::abort(bool, void*, void*) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#3  0x00007ffff6925336 in VMError::report_and_die() ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#4  0x00007ffff610f7c5 in report_vm_error(char const*, int, char const*, char const*) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#5  0x00007ffff5c16c79 in Klass::decode_klass_not_null(unsigned int) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#6  0x00007ffff5db0a79 in oopDesc::klass() const ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#7  0x00007ffff5f6d46d in oopDesc::oop_iterate(NoHeaderExtendedOopClosure*) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#8  0x00007ffff5f6d42b in oopDesc::oop_iterate_no_header(OopClosure*) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#9  0x00007ffff624c58a in VerifyArchiveRegionClosure::do_object(oopDesc*) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#10 0x00007ffff6337ff1 in G1OffsetTableContigSpace::object_iterate(ObjectClosure*) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#11 0x00007ffff624c6af in VerifyRegionClosure::doHeapRegion(HeapRegion*) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#12 0x00007ffff633c989 in HeapRegionManager::par_iterate(HeapRegionClosure*, unsigned int, HeapRegionClaimer*, bool) const () from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#13 0x00007ffff6239a5d in G1CollectedHeap::heap_region_par_iterate(HeapRegionClosure*, unsigned int, HeapRegionClaimer*, bool) const () from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#14 0x00007ffff624c953 in G1ParVerifyTask::work(unsigned int) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#15 0x00007ffff69869f5 in GangWorker::loop() ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#16 0x00007ffff6986489 in GangWorker::run() ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#17 0x00007ffff66de545 in java_start(Thread*) ()
   from /export/users/jiangli/build-64/images/jdk/lib/amd64/server/libjvm.so
#18 0x00007ffff73e7e9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#19 0x00007ffff78f34bd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#20 0x0000000000000000 in ?? ()