@Test
  public void testEntryCreateInSyncOverflowOnlyForIOExceptionCase() {
    DiskRegionProperties diskRegionProperties = new DiskRegionProperties();
    diskRegionProperties.setRegionName(regionName);
    diskRegionProperties.setOverflow(true);
    diskRegionProperties.setRolling(false);
    diskRegionProperties.setDiskDirs(diskDirs);
    diskRegionProperties.setPersistBackup(false);
    diskRegionProperties.setOverFlowCapacity(1);

    DiskStoreFactory diskStoreFactory = toDiskStoreFactory(diskRegionProperties);

    createDiskStoreWithSizeInBytes(diskStoreName, diskStoreFactory);

    Region<String, String> region =
        createRegion(regionName, diskStoreName, false, true, false, true, 1);

    region.create("key1", "value1");
    region.create("key2", "value2");

    getDiskRegion(region).testHookCloseAllOverflowChannels();

    Throwable thrown = catchThrowable(() -> region.create("key3", "value3"));
    assertThat(thrown).isInstanceOf(DiskAccessException.class);

    verifyClosedDueToDiskAccessException(region);
  }
If IOException occurs while creating an entry in a Overflow only sync mode,
DiskAccessException should occur & region should be destroyed
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/DiskRegionJUnitTest.java