Roza - From Latin name Rosa (Russian Roza) which means "rose". It corresponds to Arm names Vard, Varduhi, Vardik. It came through Russian and is a spread name.
Petrosyan - Petrosyan, Petrosian or Petrossian (Eastern Armenian), Bedrosian or Bedrossian (Western Armenian) is a common surname in Armenia.
It is a patronymic from the Armenian first name Petros (equivalent to Peter).