Degraded!

I have two internal hard drives each one is 250GB, one of them failed so i had to replace it with a new one .. but here's the output before i replace the hard drive:

Type: Mirror
Status: Degraded
Device Node: disk2
Apple RAID Version: 2
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# Device Node UUID Status
----------------------------------------------------------------------
0 disk0s3 E12E2BD9-1D24-4F57-BE8E-08C8CD3BAE61 Online
1 Unknown Missing/Damaged
1 Unknown Missing/Damaged
----------------------------------------------------------------------

I unplugged the hard drive out and i replaced it with a new hard drive, rebuild the hard drive , all seems to be ok, but unde RAID its still showing as DEGRADED, and here's the output after i replaced the hard drive:

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0 disk0s3 E12E2BD9-1D24-4F57-BE8E-08C8CD3BAE61 Online
1 disk1s3 2C1A141C-6D26-4CC1-8320-E95C71827050 Online
2 Unknown Missing/Damaged
----------------------------------------------------------------------

now I dont know about number 2, since i only have 2 Internal Hard drives .. what is the 3 one?! ..

I ran this command:

server:~ admin$ sudo diskutil repairMirror disk2 disk1

Note: Syncing data between mirror partitions can take a very long time.
There was an error syncing data between the master and the new mirror slice


Any idea's ?!


and this is the output for the disutil list:

server:~ admin$ sudo diskutil list
/dev/disk0
#: type name size identifier
0: Apple partitionscheme *232.9 GB disk0
1: Apple partitionmap 31.5 KB disk0s1
2: Apple_Boot 128.0 MB disk0s2
3: Apple_RAID 232.8 GB disk0s3
/dev/disk1
#: type name size identifier
0: Apple partitionscheme *232.9 GB disk1
1: Apple partitionmap 31.5 KB disk1s1
2: Apple_Boot 128.0 MB disk1s2
3: Apple_RAID 232.8 GB disk1s3
/dev/disk2
#: type name size identifier
0: Apple_HFS Macintosh HD *232.8 GB disk2