RAID 1 Mirrored..Not intializing the dis

Hi,
We have two servers(DB1 and DB2) which have 1
disk each and are RAID-1 mirrored. Recently DB1
went bad.We performed mirroring on Db2 which
went on fine but, when tried to mirror the DB2
second drive(new) it wouldn’t initialize but all
of a sudden the system picked it up all by
itself and started to work fine.

Can anyone help me find a permanant solution to
fix db1.

Thanks.