Originally Posted by luka
just what I thought.
I managed to get my 3x3tb drives set up into a raid5 for a usable drive of 8.18tb
had to pull my e-sata connections for the front of my tower, but I haven't used them yet so that was no problem.
Have 1 open sata slot but I might hold off on putting in the ssd, it may be easier to save it and use it for the next motherboard/cpu upgrade.
restoring my backup from carbonite is slow, but it's working. About 20% done since Sat
So RAID-5 will offer the ability to lose one disk and keep running, but as I think Rich meant to say, performance can degrade to the point of almost being unusable (depending on your application). In my experience, RAID-5 loses its value when you don't have many disks to throw at it. I just don't recall ever wanting a RAID-5 for nearly any application really; the striped parity writes take too long and too many cpu cycles, and when I have enough disks to build a storage server or am using a san/fas, I always go RAID-6. RAID-10 is awesome, but with a 4-disk minimum, it can be expensive (and heavy) in a desktop application--and while you get 4x the read speed, you still lose some on the writes. On the desktop I am currently using, I have 2 SSD's tied in a RAID-0 (2x read, 2x write performance), 3 additional 2.5" drives, and 2 2TB 3.5" drives (so that makes 5ea 2.5" drives, and 2ea 3.5" drives). I pull backups weekly, and keep one monthly. I have been running this configuration for about a year and have had no issues. I have no experience with carbonite... Wonder why it is so slow? Makes me think it does a block-for-block, forensic type copy instead of just copying the blocks with data. I guess for your configuration, I'd tie the ssd's in a raid-0, and 2ea 2TB drives in a raid-1, and use the 3rd 2TB drive for backups. But that is without knowing your application, so take the recommendation with a grain of salt.
Edit--I see carbonite goes through the cloud. Good to keep an offsite backup if your information is valuable, but as you have noticed, it can be slow and will tie up your network. I'd have an onsite solution, then pull my monthly backups (onsite) and simply ftp it offsite. Also, let's see, there was something else... right, your esata ports. You have an option, assuming you have open slots on your motherboard, to add a sata card that should provide the ability to add another 2-3 disks. That will free up your esata ports, but may not play nicely with your onboard raid. And the solution for that is... to get an add-on sata card that supports raid itself. This can get pretty expensive though. If you are having fun getting into storage, you might consider "freenas" or one of those other free open-filer type apps. You could do your own offsite backups and have granular control over the entire process.