C.Short,  You can swap the drive over, but it won't simply rebuild, as there is currently data on the hard drive. So when that drive is inserted it will display Foreign. What you will need to do is to boot to the controller (Ctrl-R) and then CLEAR the Foreign Configuration. Once completed then you will be able to rebuild the drive to the Virtual Disk, which you can do from the controller bios, or from the web interface of OpenManage (depending on OS).  Let me know if this helps. 
My questions are for a PE R720xd with the PERC H710P Integrated RAID Controller. I have replaced several RAID drives in the past, but I have never done it this way before so I was hoping to confirm my procedure for hot-swapping hard drives. A drive failed on one of my live servers. In the past I would always bring the server down during a maintenance window and replace the drive using the configuration utility to make sure everything took properly. This particular server has become a pretty high availability system so I was hoping to use the hot swap option to do it without bringing the server down. The other issue is that Dell is back-ordered on the drive I need so I am planning to use an identical drive that I recently replaced on a non-production server that has already been attached to a RAID1 array in another Dell R720 server. Any time I have ever replaced a RAID drive I have always used a new out-of-the-box drive so I'm also not 100% on how to prep the used drive for a new RAID array. I was thinking that I would bring the donor server down and just detach the drive I want to take from that server from the RAID array using the configuration utility. So one questions is - Is there anything else I would need to do prep that used drive for use in the new array? As far as hot-swapping that drive to the new array, is it really as simple as just popping one drive out and putting the new one in? Is there anything I can to do to confirm that it took - aside from just confirming that the lights flash like crazy while syncing? Thanks for your insight!
Reusing a RAID drive and hot swap proceedure