Partitioned tables on Hadoop HDFS + NFS

I am going to create a 20 TB dataset.

Can kdb use memory-mapped files on NFS? How about HDFS mounted as NFS volumes? Can I put the historical database/partitioned tables/segmented tables on NFS + HDFS? I am considering factors like

I/O-bound

network-bound

random access

sequential access

HDD/SSD

disk cache, page cache, page faults

If kdb + NFS + HDFS really works, is it better than RAID or JBOD from a redundancy or high availability perspective? Thx.

http://hadoop.apache.org/docs/r2.3.0/hadoop-project-dist/hadoop-hdfs/HdfsNfsGateway.html

http://answers.mapr.com/questions/3/memory-mapped-files.html

https://wiki.apache.org/hadoop/MountableHDFS

http://www.amazon.com/Green-6TB-Desktop-Hard-Drive/dp/B00LO3KMK0