  No.  1) There is no way to "break" a mirror on the PERC's.  The do not support non-RAID and cannot convert to a smaller RAID level (2-disk RAID 1 -> 1 disk RAID 0). 2) Forcing the second disk online so the controller can use the configuration and access the data doesn't work that way.  It will force it to reintegrate with the data already online with disk 0, likely ruining data on both disks. You can force disk 1 online and try to access its data through a live OS of some sort - or from a completely separate array - but not from the disk's companion disk.
User has a PE2600 with 2 drives RAID 1 Stripes 2.  I was called in because the server won't boot.  Both drives were offline.  I forced drive 1 to go online and it starts booting into Windows 2000 server but goes to a blue screen with a message that if it happens again to try running a chkdsk /F. User cannot find their windows CD so that is not an option.  I forced drive 1 offline and drive 0 online and it boots up just fine and I can login.  Problem is the event logs show dates before I booted up as being over a year ago.  I'm guessing that drive 0 went offline last year and they've been running just off of drive 1. So I'm thinking if I break the mirror and boot up off of drive 0 then I can look at drive 1 as a second drive and pull their data off.  Does this sound right?
How do I break RAID 1 mirror on Poweredge 2600