Has anyone encountered a "bad_alloc" error like the one below and if so, any recommendations?   It appears to be a  VM memory issue but only using 21% of harddrive space (ref: below).

  My simulation successfully completes for 200,000 ms but errors out at 98% complete for 230,000 ms, 75% for 300,000 ms and 56% for 400,000 ms.

  I'm running on NEST 2.18.0 VirtualBox lubuntu 18.04 (ref: image of settings below).

  Thank you for any suggestions.

Best Regards,

--Allen

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**** Error Message *****

>> # SIMULATION
>> nest.Simulate(300000)

Nov 21 17:10:28 NodeManager::prepare_nodes [Info]:
    Preparing 684 nodes for simulation.

Nov 21 17:10:28 MUSICManager::enter_runtime [Info]:
    Entering MUSIC runtime with tick = 1 ms

Nov 21 17:10:28 SimulationManager::start_updating_ [Info]:
    Number of local nodes: 684
    Simulation time (ms): 300000
    Number of OpenMP threads: 2
    Number of MPI processes: 1

 75 %: network time: 223698.0 ms, realtime factor: 0.6277Traceback (most recent call last):
  File "<stdin>", line 3, in <module>
  File "/home/nest/work/nest-install/lib/python3.6/site-packages/nest/ll_api.py", line 246, in stack_checker_func
    return f(*args, **kwargs)
  File "/home/nest/work/nest-install/lib/python3.6/site-packages/nest/lib/hl_api_simulation.py", line 66, in Simulate
    sr('ms Simulate')
  File "/home/nest/work/nest-install/lib/python3.6/site-packages/nest/ll_api.py", line 132, in catching_sli_run
    raise exceptionCls(commandname, message)
nest.ll_api.std::bad_alloc: ('std::bad_alloc in Simulate_d: C++ exception: std::bad_alloc', 'std::bad_alloc', <SLILiteral: Simulate_d>, ': C++ exception: std::bad_alloc')
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**** Folder Space on VirtualBox after Error ****

nest@nestvm:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            5.2G     0  5.2G   0% /dev
tmpfs           1.1G  1.1M  1.1G   1% /run
/dev/sda1        99G   20G   76G  21% /
tmpfs           5.2G     0  5.2G   0% /dev/shm
tmpfs           5.0M  4.0K  5.0M   1% /run/lock
tmpfs           5.2G     0  5.2G   0% /sys/fs/cgroup
SharedNest2     917G  447G  470G  49% /media/sf_SharedNest2
tmpfs           1.1G   16K  1.1G   1% /run/user/1000
/dev/sr0         74M   74M     0 100% /media/nest/VBox_GAs_6.0.10

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**** VirtualBox Settings *******