Do i need a CD player, or can I use Mc Book?

Unfortunately RAID does not protect from controller failure, virus, lightning or simply operator's mistake.  That's why I keep 2 backup copies instead.  Second copy is an additional protection from something bad happening during backup.  Also RAID does not protect from fire, theft etc. while my second backup kept at work does.  In addition, unpowered drives tend not to fail.  RAID might be a good solution, but I would still make one extra copy.  Drives are cheap these days.

+1.  A couple of additional things that RAID doesn't protect against:

-- If the RAID array's power supply were to fail in such a manner that it goes into an overvoltage state, all of the drives in the array could be simultaneously destroyed.  A well designed power supply will include protection mechanisms which minimize that possibility, but I wouldn't assume that all power supplies are well designed, especially in low cost consumer-oriented products.

-- Undiscovered bugs in the RAID controller's programming.  User comments that can be seen at Newegg.com about certain RAID devices include significant numbers of instances in which data was lost due to this.

Also, if the array's controller circuitry were to simply fail without harming the hard drives, but the same or a similar controller is no longer available, depending on the RAID mode that was used the data on the drives may be unrecoverable.

Regards,
-- Al
 

So I have to wonder - is anyone using "the cloud" to store their library???
- perhaps the ultimate solution

Hi Steve (Williewonka),

No, I would have to say it is not a desirable solution, at least as the primary backup solution for a large music collection.  While incrementally uploading the files for backup purposes, over time, should be fine in most cases, consider what would happen if the entire library had to be downloaded due to failure of the local hard drive(s).  Even making the optimistic assumptions that the user's interconnect connection is as fast as 100 mbps, and that the download speed is not limited by the responsiveness of the server at the other end or by any servers in the route through the Internet that is in between, downloading say 2 terabytes of music would require approximately 56 hours of non-stop downloading.  And under less optimistic assumptions about the speed of the download process, that could conceivably stretch out to several weeks.

Best regards,
-- Al