Cache creation fails EhCache on IBM z/OS USS

Question

I am trying to create a cache that could write entries to disk. It runs fine in my tests on Windows but when I deploy it on IBM z/OS USS, I end up in the following error. I have 0777 on the directory and there is enough space available on the disk. df -k gives me 405591/901440 for Available/Total. Any insights to where I should be looking to diagnose would be helpful. Following is my cache configuration-

CacheManager cacheManager = CacheManagerBuilder.newCacheManagerBuilder().with(new CacheManagerPersistenceConfiguration(new File(CACHE_DIR, "DictionaryCache")))
        .withCache("dictionaryCache", CacheConfigurationBuilder.newCacheConfigurationBuilder(Integer.class, KeywordDictionary.class,
                ResourcePoolsBuilder.newResourcePoolsBuilder()./*offheap(200, MemoryUnit.MB).*/disk(200, MemoryUnit.MB).heap(20, EntryUnit.ENTRIES))
                .build()).build(true);  




Caused by: java.lang.IllegalStateException: Cache 'dictionaryCache' creation in EhcacheManager failed.
        at org.ehcache.core.EhcacheManager.createCache(EhcacheManager.java:287) ~[Classification-Engine-Scan-Job-2.0-SNAPSHOT.jar:na]
        at org.ehcache.core.EhcacheManager.init(EhcacheManager.java:566) ~[Classification-Engine-Scan-Job-2.0-SNAPSHOT.jar:na]
        ... 19 common frames omitted
    Caused by: org.ehcache.StateTransitionException: Initial table allocation failed.
    Initial Table Size (slots) : 64
    Allocation Will Require    : 1KB
    Table Page Source        : org.terracotta.offheapstore.disk.paging.MappedPageSource@e88c7380
        at org.ehcache.core.StatusTransitioner$Transition.succeeded(StatusTransitioner.java:209) ~[Classification-Engine-Scan-Job-2.0-SNAPSHOT.jar:na]
        at org.ehcache.core.Ehcache.init(Ehcache.java:567) ~[Classification-Engine-Scan-Job-2.0-SNAPSHOT.jar:na]
        at org.ehcache.core.EhcacheManager.createCache(EhcacheManager.java:260) ~[Classification-Engine-Scan-Job-2.0-SNAPSHOT.jar:na]
        ... 20 common frames omitted