Change Performance Test button to call perftests-nas

(cherry picked from commit d3a42f58df17b769f2a7e9b35814d5a90cdfca94)
Add note about performance impact in production systems.

Ticket:	#5466
(cherry picked from commit f918ba243573f8aed9e9c1e8f7aeb4f227c9b9e4)
Do not try to predict iozone progress bar.

iozone does not offer this feature.

(cherry picked from commit fe7d3fcf9fcabd002363e65322611bb7fb31d3c5)