Reinstalling isn't that big of a deal, but we can try to recover your existing install. There is just no way to guarantee it will function again without a reinstall, since we don't know what happened or even if the disks inside are actually all members of the same RAID array holding the data.
Boot to CTRL-M (which model controller do you have?).
Go to Configure, View/Add.
If prompted between Disk and NVRAM, choose Disk, save on exit, then attempt to boot the OS.
If you are not prompted, there is one thing we can try ... I would not hold your breath though.