Hello,   Yes, the array should rebuild itself automatically once you swap the failed disk with the replacement. I would still recommend verifying this in OpenManage or in the iDRAC web interface. On the offhand chance that the array doesn't rebuild itself automatically, just mark the replacement as a hot spare. The controller will import the drive into the degraded array.   Let me know if this helps, or if you have other questions.
Dear experts: My PowerEdge R740 came with 2 SSD disks (500 Gb.) DELL sent me a new SSD and I have to replace the damaged one.  The question is: Is the RAID 1 configuration going to be rebuilt automatically? Thank you very much. Mr.Clinker
Replacing degraded SSD disk in PowerEdge R740