Mirrored RAID is NOT Backup.
Mirrored RAID merely postpones the day-of-reckoning in an attempt to keep a drive failure from becoming a data disaster. It does not protect you from accidental deletions, "crazy software" and "Just because", all common methods of data loss.
I think you have been away from the Hard Drive marketplace for a while. 3TB and 4TB single drives that would plug right into your Mac Pro (and many enclosures) are now available.
I suggest you look at some single drives with larger capacity first. ONE drive to hold everything is never the right answer.
Mirrored RAID is whatever you assign it to be...and if you assign it as the destination for your backup, then that's exactly what it is.
In 20 years of doing graphics on a Mac, the ONLY data I've EVER lost has been the result of failed drives and corrupted backups. If I back up nightly to a RAID, then even with all the other methods of data loss, the most I'll ever lose is today's work. I can live with that, and have.
Perhaps I wasn't clear. Not sure how you arrived at the conclusion that I intend to put everything on ONE drive.
My original data is dispersed across 6 drives. My intention is to place 5 NEW drives into a single Drobo enclosure, and that will be the destination for my backup. So, I'll have the original data on the original drives, and backed up copies on the RAID. At that point, my data will be dispersed across 11 drives, not one. Although the RAID is 15 TB in capacity, only 10.9 TB are available for backup storage, so that if one of the RAID drives fail I can just pop in a new one and Drobo will rebuild that drive. I'll still have the original data on the original drives.
I would have to lose one of the original drives and at least two of the RAID drives simultaneously in order to actually lose any data.
Upgrading the internal drives in my Mac Pro would give me more storage capacity for my original files (not a bad idea) but wouldn't provide ANY backup capacity, which is the problem I'm currently dealing with.
I have several Drobos and find them trustworthy. I've had a drive fail in a 5 x 2 GB Drobo FS. I replaced the drive and it rebuilt without issue. It did take about a day to rebuild though. Drobos are slow, so don't use them in any situation that you require a speedy connection (i.e. >50MB/s). Other RAID configurations may be better if you require speed.
Why would you not trust Drobo? It's capable of RAID 6. You can replace one drive with a larger drive without offloading your data and re-configuring your RAID pool. You can switch from RAID level 5 to RAID level 6 without reinitializing.
Time machine doesn't work for me because I need a bootable clone. If I'm on a deadline, I can't afford to run out and buy a new drive, then wait while that drive is restored before I can get back to work.
This will cost me about $1400, so no chance of getting 2 systems for redundancy. I'm counting on the built-in redundancy of the Drobo system.
Not sure how you arrived at the conclusion that I intend to put everything on ONE drive.
You moaned about the price of the Drobo, and indicated that it was so expensive you could not buy ANYTHING else. Then you said you were counting on it to do everything for you.
That is one device (the Drobo) doing everything. That is all your eggs in one basket. That is a situation where you blow up the Drobo power supply and it could trash all the drives inside.
I continue to recommend you invest in several higher density drives, so that you have room for all your work files and can have multiple backups. You may even want to carry a backup drive or a backup set of drives off-site from time-to-time. If you have never had a data loss, you are an extremly lucky man indeed.
I did not intend to offend you in any way. I am trying to discuss the technical pros and cons of various approaches. If I have seemed less than diplomatic, I do apologize. No offense was intended.
You moaned about the price of the Drobo, and indicated that it was so expensive you could not buy ANYTHING else.
Didn't say I couldn't buy ANYTHING else. I said I couldn't afford to buy two Drobo systems. Actually, the Drobo's not that expensive. It's the five 3TB drives I intend to put in it that are spendy.
Then you said you were counting on it to do everything for you.
That is one device (the Drobo) doing everything. That is all your eggs in one basket.
Didn't say that either. All I'm asking the Drobo to do is back up my work files. That's just one egg.
They gotta be backed up, right? And there's way to much data to put on a single drive, or even 2 or 3 drives. How is a RAID not the best, most economical solution for backing up my work files?
I continue to recommend you invest in several higher density drives, so that you have room for all your work files and can have multiple backups. You may even want to carry a backup drive or a backup set of drives off-site from time-to-time.
That IS my plan; as I said, I intend to purchase five 3TB drives. I'm just going to set them up as a RAID, and use them for backup, not install them in my Mac Pro.
I may replace some of the internal drives in my Mac Pro with high density drives to increase storage capacity for my work files, but that's not really the issue here. The issue is backing up those work files. I currently have about 8 TB of work files that need to be backed up. And that's growing rapidly with each passing month. Which is why I'm in this dilemma; I've outgrown my old backup system.
A single backup drive ain't gonna cut it. I'd need a minimum of three 3TB drives to do a single backup. How would I mount them, if not in a RAID; which now raises the minimum number to five (four 3TB drives in a RAID only gives me 8TB of backup storage; I'm instantly maxed out, no room for growth). I wouldn't go with 4TB drives, since I don't consider them even remotely economical (1TB drive = $80, 2TB drive = $125, 3TB drive = $140, 4TB drive =$300).
I'm not sure I'm clear on the backup strategy you're recommending. How many high density drives do you suggest, and how would you deploy them?
If you have never had a data loss, you are an extremly lucky man indeed.
Again, didn't say that. I said that all of my data losses were the result of failed drives or corrupted backups, not accidentally deleted files, crazy software or "just because".
I'm not offended, not sure why you think I am. Just seemed to me that you weren't understanding the points I was trying to make, so I re-stated them in a way that was perhaps a bit clearer.
I have a comparatively similar situation to you. An MP with about 8TB of material and two laptops that need backup. 6TB of which is mission critical as it contains a movie project housed on 2 x 3TB in RAID0 setup with Disk Utility internally in the MacPro, so nightly backup is a must.
I too went for a Drobo, an older 4-bay firewire one to be compatible with the laptops, and bought 4 x 3TB drives to put in it. Setting it up was no easy task, required several firmware upgrades and much googling. In the end I returned (thank you, Amazon) worried about the stability of its software and the speed of fw800. The packaging was nice though.
Although I wanted an all-in-one backup solution, I've been tempered into making a rotating solution for my critical data, thus a 5-bay enclosure with eSATA and USB (so that I can recover to a machine which doesn't have eSATA) and a Highpoint eSATA PCIe card for the MacPro is in the post. So, the backup of 6TB will cost me 12TB. When it's running I will post on this forum about my experience. I considered 2 x 2-bay enclosures, but the 5-bay would offer extra space for the orphaned 1TB disks I have lying around, so I'm looking for a suitable case for two bare 3.5" disks for the rotation and offsite keeping. Until this is running, I maintain a backup to a single 3TB disk which I have mounted on an extra drive sled for the MP.
I solved the bootable backup issue by cloning my startup disk to an SSD minus the data, keeping it in the 2nd optical bay. Booting from an SSD and running apps from it is a very nice boost to a 4 year old machine. So should the SSD fail, I have the other boot disk already in the Mac, and the data is on separate volumes.
Two 2TB USB disks do the duty of rotation for the laptops and rest of the disks in the Mac Pro, all using CCC. I looked at SuperDuper, but my own impression is CCC is more frequently maintained and with a larger user base.
Lastly, in my line of work I meet a lot of mac-using freelancers and photographers who clearly don't factor in the cost of backup when they invoice their creative work.
I adressed a similar backup situation where I wanted to back up all of the six external and 3 internal HD's) hard drives (total of 10 TB) that I have attached to my Mac Pro by purchasing an OWC Mercury Pro Qx2 4-bay raid 5 system (http://eshop.macsales.com/shop/hard-drives/RAID/Desktop/( and using it with eSATA. The software that I chose for managing the backups is Prosoft's Data Rescue 3 (http://www.prosofteng.com/products/data_rescue.php). I have used this system for backing up all my external drives for over two years now and it has performed perfectly. The Raid 5 system can be as large as 16 TB with 4X4 TB HD's). The Mercury Pro using the eSATA connection is quite fast -- fast enough to handle video storage and playback of HD files.
The only downside to the above system compared to the Drobo is that four identical size HD's must be used in the OWC enclosure. However, the cost of the OWC Mercury Pro QX2 is considerably less than that of the. Drobo system. The Mercury Pro QX2 is quiet (the fan in the enclosure comes on full when it is turned on but after 20-30 seconds slows down and is virtually silent). I have never had the fans speed up significantly even when using the Raid 5 system for HD video capture purposes. The Raid 5 system rebuilt fine when one HD was removed and replaced with a new HD although the rebuild did take a considerable period of time (typical of most Raid 5 systems).
The Data Rescue 3 software is versatile allowing for full customization of your backup, and I have found it to be very reliable.
I hope my experience has been of some help to you.