Hello k.chakchouk, Dell EMC Unity & Unity XT storage systems use their own unique drive part numbers and ordering models. Moving or using Unity DAE’s and drives in Unity XT arrays is not supported at this time. Please let us know if you have any other questions.
Hi, Can i install  D4 1.2TB 10K SAS 25X2.5 Hard DRIVE for unity  XT380 into Unity 300 ? Thanks;  
Unity 300 HArd Drive