Dell PowerEdge R710

Dell PowerEdge R710.  It is a VMHost in a cluster ESXi 5.1 build-2323236.  2 - 136G drives RAID 1.  1 of the HOT Swap Hard drive failed.  Replaced the HD with the power on and HOST was still functional but giving me an error message about cannot detect boot section.  called VMware and they said just reboot it and the problem should go away he claimed he is 99% positive this will fix it.  I migrated all VM's off the 1st host and rebooted.  Server now says no boot device.  went into the bios I see that the RAID was not configured.  so I configured it for the same RAID1.  it then said if I initialize all info will be gone.  (not so bad I can always rebuild it) I chose OK since its the only option I had.  rebooted the system again and it saying Operation:  Back Init. Progress: / 23%.  it appears to be rebuilding the Mirror.  That is my question.  is it rebuilding the Mirror?  I guess I will find out when progress is 100%.  if it was a blank RAID1 it should have to go thru this process right?  but since its taking a long time, I am assuming it is trying to recover the RAID1.  anyone care to agree?