Absolutely. You need to use OMSA to do it from the OS. You cannot expand an RAID 10/50/60 though. A PERC 6 only supports expansion by adding disks. The H700 supports it only with later firmware - I would advise updating system firmware (and drivers where applicable) before doing this.
Hello,  In a previous post, it was mentioned that you can use the OMSA to add more space to a server. You would have to reconfigure it. My only question is, can you do this on a Windows 2012 R2. The previous post mentioned was for a 2003 server
Adding HDD to R510 Windows 2012 R2