Description of problem:
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Gluster servers may soon have different virt profiles based on the VM workloads.
Currently there is only one profile with name 'virt'. But soon there would be another profile for heavy workloads. 

So volume creation dialog should have appropriate drop-down list to let the user choose the required profile. It should be also made possible to change this profile set on the volume later after the volume creation

Version-Release number of selected component (if applicable):
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ovirt-4.1.0.3

How reproducible:
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Not applicable for RFE

Steps to Reproduce:
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Not applicable for RFE

Actual results:
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Volume could be only optimized for virt profile

Expected results:
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Provide a way to enable different volume profiles on the gluster volume.

Additional info:
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Optimizing the volume does the following gluster command:
# gluster volume set <vol-name> group virt

where, 'virt' is the file containing all the gluster volume options and its values.