Description of problem:
-----------------------
HCI setup requires RAID 6 and that requires the perf team recommended values while creating pvs and vgs ( for example, --dataalignment value while creating a pv )

Version-Release number of selected component (if applicable):
--------------------------------------------------------------
gdeploy-2.0-5

How reproducible:
-----------------
Always/consistent

Steps to Reproduce:
-------------------
1. create conf file which uses - disktype, diskcount, stripesize
2. use this conf file to create the backend setup using gdeploy

Actual results:
---------------
Traceback seen while executing gdeploy with this config file

Expected results:
-----------------
There shouldn't be any Traceback observed

Additional info:
----------------

1. Conf file
-------------
[hosts]
host-sample.lab.eng.blr.redhat.com

[disktype]
raid6

[diskcount]
4

[stripesize]
128

[pv]
action=create
devices=vdb 

2. Traceback as seen
---------------------
[root@ ~]# gdeploy -c test.conf
Traceback (most recent call last):
  File "/usr/bin/gdeploy", line 177, in <module>
    main(sys.argv[1:])
  File "/usr/bin/gdeploy", line 162, in main
    call_features()
  File "/usr/lib/python2.7/site-packages/gdeploylib/call_features.py", line 36, in call_features
    map(get_feature_dir, Global.sections)
  File "/usr/lib/python2.7/site-packages/gdeploylib/call_features.py", line 70, in get_feature_dir
    section_dict, yml = feature_call(section_dict)
  File "/usr/lib/python2.7/site-packages/gdeployfeatures/pv/pv.py", line 14, in pv_create
    helpers.perf_spec_data_write()
  File "/usr/lib/python2.7/site-packages/gdeploylib/helpers.py", line 396, in perf_spec_data_write
    perf = dict(disktype=disktype[0].lower())
KeyError: 0