Restoring storage spaces after migrating from another computer

Repro Steps:

1. Set up 2012 Server, create a few storage pools (I think they were all mirrored).

2. Original server starts having "issues"

3. After attempting to resolve issues on the original hardware, I gave up and set up a new server (this time 2012 R2)

4. After physically moving the hard drives from the old machine to the new machine this is the state (shown below)

So... I know there were originally multiple pools. There's the "Data" storage pool that's showing as "degraded" and I'm pretty sure I had a mirror running across the two 4TB drives... so how do I piece things back together?

Of the two disks in the "DATA" virtual disk, one disk is listed as having an operational status of "split". What does that mean?

PS C:\Windows\system32> get-storagepool

FriendlyName        OperationalStatus    HealthStatus       IsPrimordial          IsReadOnly
------------            -----------------       ------------            ------------            ----------
Primordial              OK                            Healthy                 True                    False
Data                       Degraded                Warning                 False                   False

PS C:\Windows\system32> get-physicaldisk

FriendlyName   CanPool         OperationalStatus   HealthStatus        Usage                    Size
------------        -------            -----------------   ------------        -----                              ----
PhysicalDisk1       False               OK                  Healthy             Auto-Select                   465.76 GB
PhysicalDisk2       False               OK                  Healthy             Auto-Select                     3.64 TB
PhysicalDisk3       False               OK                  Healthy             Auto-Select                     3.64 TB
PhysicalDisk4       True                OK                  Healthy             Auto-Select                   465.76 GB
PhysicalDisk5       False               OK                  Healthy             Auto-Select                   931.51 GB
PhysicalDisk0       False               OK                  Healthy             Auto-Select                      698 GB
PhysicalDisk6       False               Split               Warning             Auto-Select                   697.75 GB

PS C:\Windows\system32> get-virtualdisk

FriendlyName    ResiliencySettingName OperationalStatus   HealthStatus        IsManualAttach                     Size
------------        -------------------           -----------------   ------------        --------------                     ----
Data Virtual Disk   Mirror                         Degraded            Warning             True                             697 GB

PS C:\Windows\system32> get-volume

DriveLetter       FileSystemLabel  FileSystem       DriveType        HealthStatus        SizeRemaining             Size
-----------       ---------------  ----------       ---------                  ------------                -------------             ----
                  System Reserved    NTFS            Fixed                     Healthy                 107.31 MB              350 MB
E                 New Volume         NTFS             Fixed                    Healthy                 148.04 GB          931.39 GB
F                 System Reserved  NTFS             Fixed                     Healthy                 302.58 MB              350 MB
G                 New Volume        NTFS             Fixed                     Healthy                 189.16 GB           696.87 GB
C                                              NTFS             Fixed                     Healthy                 443.34 GB           465.42 GB
D                                                   CD-ROM                               Healthy                          0 B                      0 B