your case is kinda interesting, but you are making the mistake of confusing backup with redundancy. if you are not a professional it might not matter but the mac pro does suggest something else.
your case is interesting, because you wanna use the storage, which is used as raid array 90% of the time, as seperate drives with one drive as tm backup.
to explain this i have to explain redundancy vs backup first:
Redundancy
- created by a raid system (except raid 0) - Redundant Array of Independent
Disks
- real time protection
- does only save you from disk failure. (mostly not multiple hardware failures, but this depends on the chosen raid mode)
- isnt save from user error, e.g. user overwrites file
- no versioning
- not save from physical accidents (fire/water etc.)
- raid should only ever be used as insurance, you only use it if you have to (by that i mean rebuilding your data when a drive is failed)
- redundancy is not backup and you should never put all your data on a single storage device, even one that offers redundancy
Backup
- More than one place for your data (physical distance between different backups)
- has versioning (depending on used software)
- more copies = safer
- online backup is possible
- Generally more important than redundancy
First, what do we take from this?
dont keep a single copy of your important data on a single storage device.
Second, what do you wanna do?
Place your Backup in the same device as your external hard drive.
Third, what makes your case interesting?
You have a case, which is meant for raid (redundancy) but wanna use it as a backup with your data next to it.
You wont have the positive effects of raid, like real time protection and you wont have the best possible effects from a backup.
And here is why we (atleast it seems most forum members) think this is a bad idea (just some examples):
- Theft --> goto z
- Fire --> goto z
- Water --> goto z
- physical accident --> goto z
- Lightning strike --> goto z
- spill coffee --> goto z
- knock the device over --> goto z
- power supply transistor explodes --> goto z
- overheating --> goto z
- Z: you just lost: start your whole life/business from scratch
Short Story: A Company with important data will have a tape drive (nowadays probably a external hard drive) built into their server. Every day, the whole year a employee will sign for this drive and take it home, every evening. The company does this because if the building suddenly inflames itself they still have the important data (because it was in a different physical location) and can keep on working.
morale of the story: do what you want, but dont blame it on someone else if you lose. Most of it seems unlikely but why did you buy a expensive raid storage device in the first place... if you dont wanna be on the safe side.
