NEVER Use A RAID As Your Backup System!


Photographers acquire A LOT of images, and that translates to terabytes of data that need to be saved and protected.

Like their shooting styles, their archive/backup schemes can be just as diverse. From RAID systems, like a Drobo, to triple redundant drives, to no backup at all.

One of the first things to remember is that an archive and a backup are NOT the same.

Backing Up Your Data

To borrow a quote from a fellow photographer’s blog, “Repeat after me three times: RAID is not backup. Period.”

For those who never heard of it, RAID stands for “Redundant Array of Independent Disks” or “Redundant Array of Inexpensive Disks.” And for those who use the phrase “RAID array,” thats redundant.

The concept of a RAID is to combine multiple, less-expensive drives into a single, higher-capacity and/or faster volume. It is designed for redundancy so that the array and its data remain usable WHEN (NOT IF) a drive fails. The terms 1-disk or 2-disk redundancy refers to the number of drives that can fail with the array remaining usable.

There are many different types of RAID configurations:

RAID 0: Its primary purpose: faster performance. RAID 0 spreads the data across multiple drives. For example, block A is on drive 1, block B is on drive 2), and this permits increased write and read speeds. This is called striping.
RAID 0 offers no protection against drive failure, since this mode does not write any duplicate or parity information.

RAID 1: This mode writes and reads the same data to pairs of drives which is called mirroring. If either drive fails, you can continue working with the other until you can replace the bad one.

RAID 5: This mode is about both speed and redundancy. RAID 5 writes and reads from multiple disks, and it distributes parity data across all the disks in the array. Parity data is a smaller amount of data derived mathematically from a larger set that can accurately describe that larger amount of data, and thus serves to restore it. Since parity information is distributed across all the drives, any drive can fail without causing the entire array to fail.

RAID 5 needs a minimum of three disks to implement. Since data is read from multiple disks, performance can improve under RAID 5. This makes RAID very good for video editing systems.


Other options include RAID 6 or RAID 10, but they aren’t often found in consumer-level RAID units. RAID levels 2, 3, and 4 are not commonly used anymore.

The problem with considering a RAID as your backup is that it doesn’t help you with file deletion, corruption by applications, operating system or viruses.

So if you accidentally delete a file, it will instantly be removed from both mirrored copies. If your disk is corrupted by a software bug or virus, the corruption will be done to both mirrored copies simultaneously.

Having all the drives in one box that is being served by one power supply and controller has its problems too. A bad enough power surge will probably fry all disks in the RAID. If your house burns down… well, you get the point.

A RAID is still a single device and because of that, also a single point of failure.

None of this means you should not use a RAID. Many photographers I know love the DROBO system. This is fine. JUST BACK IT UP! (I have never used a DROBO, but for another photographer’s opinion on DROBO see Scott Kelby’s post here:

A BACKUP needs to be a complete and recoverable copy of your data that resides on a separate hard drive possibly even a RAID. Just DO NOT USE SOFTWARE THAT MIRRORS THE PRIMARY DRIVE TO THE BACKUP or you will run into the same problems as above with at RAID 1. Proper backup software will perform a full backup and then hourly or daily backups of changed files.

My operating system and work disk (containing the current year’s photography) is backed up daily using Apple Time Machine software and a SEPARATE 3-terabyte drive. The drive is also plugged into its own surge protector. This software does not mirror the primary drives but backs up files and changed files. This gives you the opportunity to go back and recover something that may have been accidentally deleted.

The work disk contains ALL RAW files from the current year.

Images that are worked up for publication are exported from Adobe Lightroom and stored on my Photoshelter Archive. I trust Photoshelter and their geographically redundant archive to protect those images. If disaster were to strike, I could still export the images again from the backed up Lightroom archive.

My ARCHIVE of RAW images is stored on a separate drive that contains the last two year’s work. These images are also backed up on the primary backup drive.


Every year I rotate the oldest year off to a small portable drive. For these backups of the archives, I use Western Digital My Passport 2-terabyte drives. They are small and easily portable for off-site storage.

Basically everything exists in two or three places.

Whatever method you use for backing up and archiving, make sure that your data is stored redundantly and housed in more than one place. It will be the only way to guarantee its safety.

If anyone has any questions, feel free to ask!

75 thoughts on “NEVER Use A RAID As Your Backup System!

  1. Looking at your diagram, am I correct that you have four separate drives coming off your desktop: one for the system software, one for work files, a third for images for the last two years and then a large 3TB drive holding everything? If so, mind if I ask what type of drives, sizes and enclosures you’re using for each of those. It also looks like you’ve foregone RAID. Are you using Time Machine for backups or making bootable backups with something like SuperDuper?

    • Hi PJ

      There are actually 5 drives attached to the Desktop machine, 4 of them are internal to the tower. (The system disk 500MB, work disk 2TB and 2 scratch disks 1TB each). The 3TB backup is external. All drives are Western Digital.

      I have a bootable backup of the system disk which is simply another internal drive that is not installed. I can pop it into a docking station that is generally used to diagnose disks if I need to boot from it. Of course since the system disk has nothing on it but the system and the applications, I can also do a pretty fast recover from TIME MACHINE of that drive if needed.

      Yes I use TIME MACHINE.

      The problem with the RAID 1 as your main drive is this. If you delete a file, it is deleted on the mirrored copy as well. Same issue with corruption. The drives in the enclosure mirror themselves in real time. The only thing a RAID 1 protects against is a crashed drive.

      RAID 5 would offer better protection and the RAID 5 draw is speed. But truly, unless you are doing a lot of video or sound work, I don’t see the need. AND even though you can recover from a crash, you should talk to people that have had to do so, IT CAN BE PAINFULLY SLOW to rebuild the failed drive. It is doing so by using parity data. It is not a simple copy to reload the data. Of course this drive would also have to be backed up. I am unclear as to whether you can recover a single deleted file from a RAID 5. Its main purpose is speed and ability to rebuild a lost drive.

      My laptop is backed up with TIME MACHINE to a portable drive. Here I am mainly concerned about the SYSTEM files and other things like accounting that I have on the laptop. I transfer daily work off each night, so I am not too worried about that. Usually by that time, worked up images are on the way to the client and have been sent to Photoshelter.

      Yes the small WD My Passport Drives are great for long term archive storage. I simply buy 2 at the end of every year. If you look for deals at Staples or Office Depot you can usually get one for about $120.00.

  2. Thanks for this article Pete – PERFECT timing for me and I plan to adapt this myself. I’ve had a Drobo, it was a nightmare, finally turning into a brick. As I rethink my backup system, I’ve gotten myself totally confused with RAID 0, 1, 5, etc. I embrace the concept of backup being more than drive failure replacement.

    If I use Time Machine to for my main backup, what [software] do you use for your on-site and off-site backups? I thought that TM could only backup a working computer – might you elaborate a bit if you drag and drop, or maybe use another program front the archived backups?



    • Hi Greg. I do not have an off site backup for the general system. The image files from each year are exported from Lightroom as a catalog to separate externals for off site. And of course all of the “worked up” images are stored on PhotoShelter.

  3. Pete,

    I have just spent the best part of the day looking for a longer term solution to back up my photography. I have learnt a lot about the pros and cons of RAID and proprietary systems to then find your article, the best on the net for my purpose. It also turns out that it is pretty much what I am already doing, though I am doing it manually. What software do you us for your differential backups? (possibly time machine? I am PC so if that is the case I will need to explore some more).

  4. Use a Seagate 1 TB USB drive, built in software allows you to choose the time of day and daily schedule of the backups to the drive. I will be using a 6 drive Raid 10 solution for a t620 enterprise server. I will be using the Seagate for a backup of the sql database. The seagate will be left in a fireproof safe with a hole in the back for wiring.

  5. Nice right up. Raid 5 is not for speed, its actually slow on rebuilds. Raid 0 is for speed then raid 1 then raid 10. Raid 0 if one drive fails you are dead. Raid 1 you can loose one drive and still keep working. Raid 6 and raid 10 can loose 2 drives with 6 being slower on rebuilds. Raid 10 is probably the best for speed with Raid 6 being better for getting more space per drive when you go past 4 drives. None are for backups but for preventing downtime and data loss.

    But I think your backup drive should be raid 6 or 10. ZFS files system is also nice to prevent bit rot. Lets say you need your backup and its on just a solo drive and that drive has bad sectors. That backup is no good. That same backup on a good raid with zfs is very unlikely to ever go bad. Of course if the building they are in blows up then its all gone so offsite is smart.

    • I think RAID 1 can be used for redundancy, but not backup. As the author here write, if you delete one file, you delete them both – this is true also of some backup schemes, though also.

      I think RAID 1 will beg you back up and running faster than no raid at all. But I am inclined to agree, redundancy is not quite the same as a backup. For day to day recovery from mistakes or misplaced files, a regular backup is better. But I am not so convinced that it replaces RAID 1 for a catastrophic failure. I think both backing up files and RAIDing systems is a best approach.

  6. Thanks for this article – I just read one today suggesting to use RAID – for now, due to the small volume of photos, I use a couple of external drives to save my work.

  7. I was about to impulse buy a Drobo and at the last minute I found your article! Thanks! It gave me the pause I needed to do some research first! I’m sticking to my three WD My Passport drives for now.

  8. Great article, its january 4th and Im sitting here wondering if I need to change my system… a disc has just got filled up, so I need to buy new ones…. I use large storage discs and back them up with chronosync, which is excellent. Many thanks for this piece, it helps to know that Im not the only one with this eternal headache! Mark (interior and lifestyle photography) (Fine leather camera straps, made in England)

  9. The biggest issue with RAID are the unrecoverable read errors.
    If you loose the drive, the RAID has to read 100% of the remaining drives even if there is no data on portions of the drive. If you get an error on rebuild, the entire array will die.

    A UER on SATA of 1 in 10^14 bits read means a read failure every 12.5 terabytes. A 500
    GB drive has 0.04E14 bits, so in the worst case rebuilding that drive in a five-drive
    RAID-5 group means transferring 0.20E14 bits. This means there is a 20% probability
    of an unrecoverable error during the rebuild. Enterprise class disks are less prone to this problem:

  10. Questions:
    Q1 a&b: What is is the problem with Raid-1 using Time Machine? …Won’t I end up with TWO Identical Time Machine on the Raid-1 external drive dedicated to back-ups using Time Machine program? … that isnt that superior to having just a single external drive back-up?

    Maybe there’s something I don’t understand in your article “NEVER use Raid for a back-up”. I will appreciate your answer as I plan to purchase a Western Digital “My Book Thunderbolt Duo 4TB Dual-Drive with RAID” to replace an older 2TB “Iomega Companion for Mac’ that I’ve using… and use the new WD MyBook external drive in Raid-1 conficuration so I always have two back-up time-machine copies of everything.

    My thought is that for additional back-up security, I could even switch out one of the removable/replaceable drives in WD “MyBook Thunderbolt Duo 4TB Dual-Drive with RAID” the on a weekly so I have also have an offsite copy thats no more than a week-old at any given time in case of fire other catrastophe at the physical site of my digital workstation.

    Any answer or further explanation will be appreciated. Thanks

    Becase the WD …. and a third off site if I follow-thru w/ the

    • RAID software instantly mirrors one drive to the other in the RAID. If your time machine backup software fails or corrupts during the backup, both sets of data will be corrupted.

      RAID gives redundancy, IT IS NOT a backup. Yes you can use a RAID array as your backup drive, BUT if the array fails you still need a backup that is stored on an entirely different physical disk. The second drive in a RAID 1 array IS NOT that different disk.

      When you configure the RAID 1, you will never see two drives mounted on the desktop. If one of the drives in the RAID fail, you will be notified by software that the drive needs to be replaced and once you do, the firmware will rebuild the mirror. RAID 1 is NOT an automatic backup!! But in situations where you cannot tolerate downtime, this will keep you running until you can make repairs.

      The best best option is to use TWO SEPARATE DRIVES for backup and let Time Machine do the work and eliminate the complexity of the RAID.

      Time Machine can be configured to work with multiple drives and alternate backups between them. This way if one of the backups were to fail, the other will be available.

      Hope this helps.

  11. Thanks for this! I found extremely helpful. I’ve inherited a small personal library of some pretty great footage. It all on lives one shared RAID drive. Editors work directly on this drive and once their down they create a new folder called, “exports” but it still lives on the shared RAID.

    I’m trying to fix this, and feel a bit lost in the process.

    Here’s how I understand the workflow (please correct me if I’m wrong):

    Original files get imported into the RAID as a new project name (with a batch rename of all files for future ease). This gets backed up through Time Machine at the end of everyday. Editors can then go in and create complete projects, which will ALSO get backed up through Time Machine.

    HOWEVER, what about an off-site storage. This is where I’m getting lost. How often do you have to bring the off-site 3 TB drive to get updated? Does it automatically know which files are new and where they belong? How do you make sure projects stay complete and together when it backs up and updates files?

    Thanks in advance!

  12. When I was looking to backup my RAW photos and files in general, first of course I do ue time machine. But, I wanted offsite data (home office) and looked at dropbox as a solution. I can backup the same data as I do on time machine and it has the added feature of being able to recover deleted files (extra fee). Now I’m also looking into Amazon’s cloud storage, haven’t looked into it much beyond around $70 a year for unlimited storage. If that’s true, I could even mirror my time machine if I wanted.

    Is using multiple cloud storage for backup like this come off as just inane or is it a practical solution for backup? If Amazon is basing their cloud on their S3, wouldn’t it be both reliable and with unlimited storage, can both mirror time machine and store older data in conjunction with other cloud services which now includes Microsoft getting into the game with enormous storage at a very low price.

    I don’t know where and how secure dropbox is if they had a major failure, but certainly Amazon and Microsoft are likely to be secure even if major failures occur.

    One last note is that while it’s not a cloud solution yet, Google has nearly completed their system for “perfect” reliability. Impossible for their search engine and the data they collect to be lost.

  13. Hi!

    Your article is very learnable to read, as I the last four years used to save all my photos I´ve been taking the last 10 years on a RAID 0 using two 1 TB internal hard drives.

    Last week, the PC lagged and there was some strange clicking noise from it, and after rebooting, I get an error message the RAID 0 was failure and it will take a long time to start Windows. And in the BIOS I can see only one of the disc´s can be reqognized.

    I know I should blaim myself to be stupid for having no backup! But may it be some change to retrive some of the lost data, without leave to a professional costing up to $1000?
    Are all files splitted to the two disc´s, or may some files be at only one of the disc to maybe be recovered if take the RAID away?
    And if I try do so, can´t it be set as RAID 0 later if I will then try to start the bad disc again? Or maybe I should try the freezer method!?

    Best regards: Mikael Markstrom

  14. Very helpful info – thanks.
    Just as a side note ~ I came here as my Time Machine backup has failed. So I’m not sure it is trustworthy software. I have random folders & subfolders to the tune of 150GB missing from my 800GB TM backup. Apparently your OS X system records of what has been modified can get errors & then that stuff is ignored by the TM backup over time. Luckily I noticed this before I actually needed the backups!

  15. another problem with RAID: even the most elegant pre-configured solution in the market, Drobo, has tremendous risks, as famous photographer/author Scott Kelby complains in 2012-06 there’s no point in raid that constantly monitors the health of HDs & auto-shifts data to healthy drives if the drives keep failing due to software/os/virus/shortcircuit etc. + if you use proprietary system as Drobo you can’t plug drives into different system to recuperate files

  16. Hello everyone! When I recently upgraded my internal drive on my iMac 2009 27″, with a new HDD combined with an SSD for the OS and applications and found out that although we technically have a infinite amount of knowledge and information about back-up systems we seem to omit talking about the actual experience of having to restore your system within our blogs, which in my opinion is just as crucial. The user thus has to search about restoring a computer, which to my opinion requires just as must research than the time spent on understanding back-ups. Why are both subjects so appart from one another. For months I spent time looking up solutions (softwares and hardwares) and they all sell how good they are with backing up and how easy it is restoring, which to my surprise IS NOT as simple as one might think. From a blogger (and god thank him) I took the following precaution which saved me a huge headache. Even before I started, I created a bootable drive on a USB key in order to install my OS back onto the new SSD. From what I read and experienced, this saved me huge problems not mentioning a lot of time!

    I also found out that Time Machine has issues with backing up huge files and often stops the restore process when the size of files are too big. If you use softwares such as iPhoto and Aperture and your libraries are consolidated, then that creates an issue you would not have with a “Referenced” library. Look this subject up.

    This being said, I feel that regardless of your approach with back up systems, you need to test and document restoring your back ups before you system does crash. This will ensure the user has a plan and knows how to proceed when all fails!!!…..


    • Nicely spoken! I have crashed so many times in the last 20 years and learn something from each. But wisdom is learning from other’s mistakes too.

  17. RAID, especially RAID 1 (AKA Mirroring, is indeed a viable backup solution. However, it is NOT a whole backup solution. In the heyday of the mainframe, before PCs and the Internet, mirroring data was highly desirable way to backup your data.
    The reality of how safe your data is using TAID is contingent upon severak factors::
    1. What level of redundancy do you really need?
    2, How much do you Have to spend?
    3, How well protected is your data>?
    Most home users do not require 24/7 by 365 uptime. Some businesses might. This will determine how deep your redundancy needs to be…. RAID, Mirrored disks with dual controllers, Mirrored systems ae all options depending on specific needs. The bottom line is that RAID mirroring protects against a single disaster; hard disk failure. It does that very well.
    However if you get hit by a virus, accidentally delete data or have corruptions not causd by hardware failure, RAID will most likely not help you. Remember that hard disks are mechanical devices with are expected to fail eventually. This is the specific purpose of mirroring.

  18. Mike Chambers is exactly right.
    I would like to point out that there are software and hardware RAID solutions with hardware being the preferred and safer option.
    My workstation has a single RAID 5 array consisting of three 2TB SAS drives plus one hot spare. If one drive fails, the hot spare is automatically used to rebuild the volume. The RAID controller’s software would have notified me of the impending failure, actual failure, hot spare rebuild…etc. I also use a RAID 5 NAS device with the same configuration. Unfortunately, off-site/cloud backups are not an option due to my bandwidth limitations. Any single hardware RAID option is superior to a single external drive and I would feel much better having a good RAID 5 setup over multiple external USB drives. The only benefit to external USB is its portability.

    • Anyone who just uses a RAID as a backup is asking for trouble. As Mike Chambers said…. “RAID mirroring protects against a single disaster; hard disk failure.” Also, if you delete a file, it is deleted on the mirror. If a file corrupts, there is a excellent chance it will corrupt on the mirror. Saying that off-site backups is not an option is ridiculous. You may not be able to use a cloud option because of the bandwidth, but you still need off-site backups. of the RAID. RAID IS NOT A BACKUP.

      For more information please read:

  19. Yeah??? But Raid1 is my backup! What happens if your 3 tb drive crashes? Everything older than two years is gone unless you got another backup some wheres. Get another 3TB drive and make a 3TB raid 1 array. Don’t use Raid 1 for your main drive. Instead, use it for you 3TB backup system. Make incremental backups to the Raid 1 backup system Any file you accidentally delete from your main drive will still be available on your Raid1 backup device. If one of the 3 TB drive crash, you will still have your data on the other one. Never delete data from the Raid 1 array. Let your backup software do that. I use raid1 for a backup up array. It works fine without all the difficulty trying to use Raid1 for your main drive entails. Yes, a raid1 main drive is not good idea for data preservation. Instead, it’s better used for main drive to allow a system to keep running if one of the hard drives fail. Put data somewhere else. I do incremental backups to my Raid1 array all the time. It works fine. It doesn’t delete a file from the backup when that file is no longer present on the main drive. I don’t let it delete anything I don’t want deleted. Deleting something on my drain drive doesn’t cause the file to be deleted from my backup raid1 array. I use Ubuntu’s Backup utility to backup my data to a software Raid1 on another machine. The incremental backups take no time at all. Use the imagination! Main drive raid1?? Nah, not for data preservation! Instead, backup your data somewhere else. That way, if you accidentally delete a file from your main drive, you can go get it from your raid1 backup device. You can even get older versions of the file from your raid1 backup device if you changed it at some point.

    • You apparently did not read the post closely. If the 3 TB drive (this is actually now a 6TB drive) crashes I get a new one and back up the system again. It is the BACKUP not the work disk or the system disk (these are on two separate drives). As for the drive with the last two years of work, if you look at the bottom of the diagram, there is a separate drive with each years work stored in a watertight case on site. There is also another copy of each of those drives in a safe deposit box.

      Now when talking about your RAID1, you say “If one of the 3 TB drive crash, you will still have your data on the other one.” Yes that is true, UNLESS there is a controller error (which effect BOTH drives), or if the data on the first drive corrupts (and this happens), it will automatically be mirrored to the other. If the RAID software reads garbage from the first drive, it WILL write it to the second drive. It does not know it is garbage. The software does not know if a file is corrupt, it is all 0’s and 1’s and they all get copied. RAID doesn’t protect you against a file being deleted or overwritten.

      One last thing, there is also a difference between a backup and an archive. Backups are for a recovery process and archives are for the retrieval of information. Backups are copies and archives are originals. Backups are usually done with proprietary technology and archive technology is usually open standards, so material can better be retrieved years from now.

      The idea behind archiving is to take that material out of your system and putting it somewhere safe.

      • I can’t argue your points. They all seem valid to me. I originally didn’t understand that your approach had backups offline. I’ve heard that I don’t need to be able to read fast, I just go to be able to read! However, I don’t differentiate between archives and backups since my system contains every data file I ever created and which I want to keep.
        To prevent loss of data, I back up my system routinely to a raid 1 array. I recovered a couple files I accidentally deleted from my system. Otherwise, I’ve never had to use it. After the initial backup, I make only incremental backups since it seems unnecessary to backup something I already backed up before. If the array completely fails, where it isn’t recoverable, then I still I have my original data and can simply create a new array after replacing the failed components on the backup device. I was only suggesting that Raid 1 is a perfectly suitable medium for backup data. The idea is not to run the system on a raid 1 array and expect that you don’t have to backup. Instead, run a raid 1 array for on another device for backups. To loose data, I need to have my mains system drive crash as well as both drives in the Raid 1 array. I feel lucky!

  20. Just FYI, Drobo is NOT a RAID array. It performs in a similar way to RAID, but with a lot fewer restrictions (i.e., maintaining disk order, same disk sizes, etc.) Having said that, you are correct about disaster recovery vs. archiving.

    • This post was written originally before DROBO deployed their “BeyondRaid” technology. But truthfully, the only thing scarier to me than the traditional hardware based RAID would be a proprietary software based RAID.

  21. Wow, amazing wealth of info here. I may have missed it, but where do I learn how to setup a RAID 5? I do tons of HD video editing on my MacBook Pro and have almost filled all THREE of my external 5TB USB 3.0 drives (yes, 15TB is a lot!). I think what I want to do is connect them together as one (a RAID 5) and then have another setup as a backup. This would avoid the nightmare of plugging drives in and out and trying to figure out which things have been backed up.

    Sound logical / correct ?

    If so , how do I create the RAID 5?

  22. I must say for a Non tech (I am assuming that) or in your case a photographer you are quite adept and your methods are solid. You can recover data from Raid drives but it will be expensive. Have had to do it several times in my career for clients that simply had no backups or never tested the backups. Never lost data in 25 years in IT doing storage and Server management. Not that I am sure it is possible data is irrecoverable but I have been lucky enough to always be able to recover though it has cost some big dollars a few times for the client that did not listen.
    I have trained many Photographers and Photo Booth Operators and know that you are a very smart group in general. Rarely am I asked more questions after the first 6 months unless its things outside the scope of the shop they are running.
    As to Raid I would highly suggest Synology devices for your backups. They are extremely well made, very versatile and I have heard so many positive experience reports and few bad ones. I do agree 100% in the policy of having 2 backups of your data. One is simply not enough. Plus an offsite cloud copy is a great idea as it is so inexpensive. BackBlaze is $50 per year unlimited for one machine. Other deals offer 1 TB at $50 a year unlimited machines and there are offers with Synology now for some cloud backup that is very reasonable such as $10 TB per month. Amazon has a new low cost offering as well. JungleDisk is another excellent choice. For Windows software SyncBackPro is excellent as its Touch add on software can backup even Android phones. Quite amazing,

    So if it was my choice I would have Raid 1 on the OS drive and I agree as you stated it is only to avoid being down if a hard drive fails as it serves no other purpose. But it does that very well and drives fail. I just built a Raid 1 SSD machine for a client. He loves it.
    Next a Raid backup unit and as large or as small as you need are available and Synology has been extremely solid from low end to high end.
    Lastly a USB hard drive as secondary backup. An 8TB USB Drive from Seagate is $250. So you really could buy several if needed or smaller drives if not including the Passports you are using which are just fine or the smaller Seagate backup drives.
    Great writeup but I believe the most important thing is off site backup as well as on site. If you use only 1 drive for OS and data, then 1 USB drive for local daily backup (using TM is great) and then something in the Cloud with a copy of the local backup drive should be the minimum. That way it would be very hard to lose everything especially if you use a good cloud backup with differential backups allowing you to go back as many days as needed to get before possible corruption or the Spyware that Encypts your data and holds it hostage till you pay. The FBI says you should pay. Seems like they must be behind it to say that. Why not say HAVE DAILY BACKUPS. JungleDisk is a perfect cloud backup system. I sell it but I am not giving my links here as I mention it only because it is great. Go to their website and try it..

  23. Pete,

    Thanks for this superb article.

    When responding to PJ you mentioned two internal scratch disks. I’m assuming the first scratch disk is listed on the diagram as “Last Two Years Work” that also contains the raw files from the last two years. What does the second scratch disk contain?

    Best wishes,

    • Hi Jen. This post needs to be updated since I have since replaced the tower with an iMac 5k Retina machine. So there are no longer internal drives (except for the 500GB Flash drive). I plan to update this post soon.

      But to answer your question, the extra scratch disk was just a temporary storage place for misc. stuff.

  24. I agree and also disagree with “Never use raid as your backup system”
    1. Agree that raid is not a substitute for a backup.
    2. Disagree in using raid on a backup system.

    I use NAS for backups and all of my NAS are raid 1 or raid 10.

    So you can and should use raid for storing backups.

    I think the confusion comes with people using raid and thinking its as good as a backup. Its not. But if you want to make sure your backups are viable I would store them on a raid 1. Then it is less likely when you need to go to that backup that its bad.
    I use ZFS with scrubs + ecc to ensure no bit rot creeps into my backups too.

    If you can’t use raid for backups then I would suggest keeping multiple backups on cheap usb drives.

  25. I believe I may be asking a similar question to Doug on the 25th Nov 2015. I have a new iMac and an external Pegasus R8 array which comprises 8 x 4Tb drives (= 32Tb) set up in RAID 5.
    I also want to have all the image files contained on the Pegasus backed up twice. I already own some older Sonnet Fusion enclosures (2 x 4 drives = 8 total) and can max those out at 24Tb which is more than enough) but my question is what is the best way to ‘mirror’ what is on the Pegasus? Do I separate the info on it into a series of folders say 1-8 and simply do a Raid 1 set up ie mirror each folder to each corresponding drive on the Sonnet? Or is there a much smarter way, ie RAID 5 on both? I would intend to take the Sonnet drives off site periodically and swap them over so hopefully everything is backed up in triplicate.
    Many thanks for any enlightenment! 😉

    • The Raid 5 should be considered at one big drive as far a backup software in concerned. But this is where you have created an issue for yourself. Since you feel you need to have 32 TB of data readily accessible, you need a 32 TB drive to back it up. (or should have anyway)

      Unless you are doing high end video work and need that much space to work, you would be much better off and safer using smaller separate drives which can easily be backed up.

      In my work there is no need for me to have raw files, from 3 years ago, online and accessible instantly. I have those on separate drives (by year) in a case near my computer if I need them. Their backups are in a safe deposit box. All of my “worked up” files that are ready for publication are on PhotoShelter.

  26. I get what you say about RAID as a back-up system but I would argue there’s nothing wrong with it as an external drive storage option if your primary machine is a Macbook and you dont have the option of multiple internal drives.

    One related question: I have a Mabook with about 700 gigs of used storage and an external drive holding 648 gigs (mostly photos) which I’m backing up on a 3 TB Time Capsule. That feels a bit small and its going to feel tighter – I add about 125 gigs a year (shooting a D800). Time Machine doesnt offer the option of spanning drives. Any solution you can suggest?

    Second question: Is there any point in using SuperDuper if I’m already using Time Machine?

    • I never really considered options for backing up if my only machine was a laptop.

      As for the Super Duper question, I use Carbon Copy Cloner to back up my Macbook since I need to have a quick recovery ability if traveling. I also have a copy running on the desktop to create a bootable copy of the system that I can use quickly.

  27. What happens when the 3TB fails? Shouldn’t it be RAIDed to replace the disk to preserve the data? I don’t know if you can have a RAID back up with a separate non-RAID OS disk setup.

    • The 3TB IS the backup. On it is the backup of the system from the tower, the work disk backup and the backup of the last two years disk. The last two years are also on separate drives that are stored in a safe deposit box.

      This setup has been changed recently since the tower has been replaced with a 5K iMac. Post update is forthcoming.

  28. Pete, I’d appreciate your assistance with current and planed workflow:

    Here is my scenario. I have a 2014 Macbook Pro with 3 external Dell 24″ monitors connected to it (2 via display port and 1 via HDMI). I come in from a shoot and take my SD card, dump it to a new folder on my MBP. Edit, and then move to a primary external drive (passport 2TB). CCC then copies any new changes to another 2TB passport AND a 4TB G-Drive. All new data is also uploaded to Crashplan and Time Machine is also running. I lost 177gb of data 3 nights due to a corrupt drive. I was able to recover it using Data Rescue. What’s funny is that the only reason I had to recover anything was because I hadn’t moved data from my laptop to my external drive in about a week. My backup process was there, I just got lazy.

    So….I was about to updgrade to some larger drives anyway and since I just saved $1000+ since I didn’t have to send my drive off for recovery, I want to up my game. I like the portability of my MBP BUT part of the reason I didn’t back it up over the past week was that it wasn’t at my workstation…it was with me. I am considering adding another iMac 5k to my house but this one to be used as my primary editing machine…still keeping my laptop but really only for portability. Since I have three monitors and they take up my two display ports (assume at least one of those is the Thunderbolt port) and HDMI port, I picked up a Thunderbolt hub to connect the monitors. Tomorrow I’ll get my iMac 5k and two OWC ThunderBay 4 RAID 5 in 16TB and 20TB.

    The plan was to setup the 16TB as primary and 20TB as backup. Even OWC suggested that. What am I missing?

    • Seems reasonable to me. The weakest link for me also is the time span between the shoot and the movement of the new files to the desktop system. I try to be diligent about the transfer so that if the macbook crashes, I have a backup. I think I am going to get a wi-fi enabled WD My Passport to keep nearby to backup without me having to think about it.

      Since this post, the setup has changed since the tower has been replaced with a 5K iMac. Update to the post is forthcoming.

  29. Still don’t get why RAID can’t be used for backup. If your external drive fails and you don’t have other copies of the data its gone. On the other hand if the external drive was run via a 2-hub RAID1, one drive could die and you still have your backup save on the other.

  30. Raid 1 should only be used for servers to duplicate the boot drive. No other situation calls for Raid 1 because it’s usually a waste of space and a lot of wear and tear. Production servers are the only ones that need that kind of redundancy.

  31. Thanks for this wealth of information. +1 on avoiding a Dobro. I worked at a radio station. We used a big Dobro to backup our 10 Pro Tools workstations with Retrospect. The Dobro was always causing problems so backups often didn’t happen. Retrospect was problematic too. The entire setup was a big kluge. We finally dumped the network solution and put an additional Time Machine drive connected locally to each workstation. That was fine, but we really should have used dual drives configured for Raid 1. A single drive can (will) fail. Now the chances of your backup, or should I say archive drive and your system drives failing at the same time are small, and we never had it happen. But for mission critical work, you should have 2 local copies and an off site solution.
    One more point. Surge protectors offer little to no protection. A power failure can screw you and surge protectors don’t suppress all surges. Once they get hit hard, most fail and offer no protection and you probably won’t know that until it is too late. The best solution is a UPS where the line input charges the batteries and the output power is always supplied by the batteries. That is probably the most reliable and affordable surge protection. Plus, most UPS units can shut down your equipment before the batteries run out of power during an extended power failure.
    This is how I have my home/studio set up. All computers back up with Time Machine to a 10TB mirrored raid connected to my studio computer on a UPS that will shut down the computer safely if there is a long power failure. I also backup my really important work to a cloud. It’s slow and a pain, but it’s cheap insurance for the stuff I can’t live without. Been working this way a long time and never lost any data. Had local drives fail, but the Raid saved my ass every time. Never had to go to the cloud.

    • Hi Steve and others, Your configuration sounds worth investigating further for our requirements. I’m in the same situation. Could I ask what cloud service you are using? was it easy to configure? and what mirrored raid level.
      Glad it’s working and I’m looking to avoid an eventual single drive failure. I have a number QNAP NAS systems 8TB, 24TB and 96Tb for large HD video files. I don’t look forward to backing up our mission critical data!

  32. I think the article is not clear enough. RAID is NOT a backup strategy, so it has no sense at all. RAID purpose is to offer some sort of redundancy in order to provide more reliability on the data availability. Another point: using Hw based RAID will have more reliability than Sw based RAID (it’s more expensive, but is “safer” also). Using RAID6 with at least a Host Spare will offer the most reliability at a RAID support level.
    Now, backup. A backup consist in a policy and strategy to save (backup) your data in the best adapter manner for your use. What does it mean? That using a good backup strategy will be based in the policy you needed to backup your data, according to some parameters (Google it, Time To Recover Backup; RTO, RPO). And… YES, you can use RAID based enclosures to perform this operations! Of course! that’s what the industry in fact currently recommends as it reduces both RPO and RTO and help you have your data available almost every time. It’s also recommended, in a case it is really critical to have your solution synchronized with another storage enclosure. But… just saying “don’t use RAID to backup your data” it’s a fallacy 😉 Just, read more, learn more.

    • The title might be misleading and I am due to update this since my configuation has changed. But the point of the post was to address the people that were using a RAID (such as a DROBO) as their main work storage and assuming that since it was mirrored, that it was backed up.

  33. I’ve used the same backup strategy. using time machine instead of RAID. However on several occasions it has happened that all of a sudden, time machine completely erases itself and starts over from scratch. This terrifies me. Have you run into this as well? I’m wondering if time machine does this when it runs out of space, or if it’s a maintenance thing, but I’m terrified it would start doing this when I really need to retrieve something.

  34. Nice article. Well written! Informative! Thanks. I used to but have not recently, switched hard drives every 6 months to a safe deposit. So your two years 2012 and 2011 would be off site, and most you could lose in fire, etc would be 6 months instead of 24 months! Thoughts??

    Greg T.

  35. I have a IMac deskop 27 x 3 years old – have 2 8TB external hard drives which contain about 14TB of storage – really scared to lose my images – I was about to buy a QNAP raid simply for back up – have no other purpose for the Raid other than to have a secure back up – I am very unsure what to do now having read your excellent report I have loads of hard drives in my cupboard which is the reason why I was thinking about the Raid

    • Hi Gavan

      I am assuming from what you are saying that you have 14TB of images on those two drives. My first question is do you need to have all 14TB of images online (I use the term online here as meaning connected to the computer and accessible instantly) at once. Sounds to me like much of that could be archived, i.e. placed on offline drives and stored (at least 2 copies in different locations). IF that is the case I would archive as much as possible and then use 1 8TB drive for storage and one for backup, moving older images to the archive as you need more space on the first drive.

      I have received many emails saying that you can use a RAID configured drive as a backup drive. Which is true. My headline is not as clear as it should be. My point is that having a system where a Mirrored RAID (RAID 1) is the primary drive AND the mirror is the backup is a very bad idea. But you could use a RAID (4,5 or 6) as the backup drive if you really have to have both 8TB drives online and backed up. The problem, of course, is that eventually having all these images online at once will be unmanageable. And most likely there is no need for it.

      I recommend archiving the older images and keeping your online storage and backup at manageable sizes.

      Hope that helps.

  36. Just a short question. I have a 12 TB Raid 0 on a Lacie 2Big. When I want to move on, could I just take out the 2 disks and store them as backup and use two new disks for new work? Would the 2 old disk work as backup meaning when I put them back into the LaCie, would they still work of will the Raid be lost or at least risky? I hope my question is clear .

    • Hopefully, someone may be able to help you better. My concern would be if the RAID is being administered by hardware in the unit or by software. If you pull the drives out and then replace them in the same enclosure and the RAID is being administered by hardware in the enclosure, all should be OK. Of course, if something ever goes wrong in the hardware, you probably will not be able to use those drives as a backup unless you find another Lacie 2Big.

      Since I don’t know much about the LaCie drives and RAID implementation, I can’t be much help. But I think it is a risky proposition.

  37. thank you all for the ongoing learning(and sharing) discussion. storage, backups, archiving is so critical to our lives now, and new technology continues to try to adapt to offer usable options to address these growing complexities. remember when 1MB sounded like an enormously huge file?

    my question is related to Hard Disk Drive size, iCloud Drive, DropBox(Google Drive etc etc…) (assume I’m backing up with Time Machine on several separate local ext hard drives of adequate sizes). even taking home several other HDD home with me for offsite backup storage).

    in my case, i use both iCloud drive, and DropBox. i store my entire Photos Library on iCloud, with pretty much every document file I’ve created, stored/filed on DropBox(i may make an alias of a folder on my desktop for folders i access most frequently). i know DB can be arranged to ‘selective sync’ folders that i don’t need on my local drives like laptop: MBPro,( but could still access via account as long as i have internet service). my growing concern and problem running out of Disk Space. iCloud Drive stores all files on local HD; DB can upload files to server. with 1TB storage on my Mac Pro(tower), I’m essentially running out of internal disk storage space to continue to hold my growing Photos library,( and LR Catalog folder). my Photos library(downloaded originals) alone is getting close to 800GB( BTW, i don’t store any video of professional web content we have produced, on any local disk, only on external Drives). if i attempt to store a backup of the Masters folder (Mac HD/Users/HomeFolder/Pictures/.Photoslibrary) on DropBox it stores redundant files on my local HD… my MacPro has (max) 1TB SSD. what happens when my .photoslibrary gets bigger than 1TB?

    where does anyone store their original .Photoslibrary or LR catalog folders, if not on the computer’s HD? external HDD are bigger, and cheaper(?) than internal disks; can i place my .photoslibrary on an external drive? will it still sync with iCloud? Can it still be used with Time Machine to back up somewhere? whats the probability of corruption with any set up like I’m talking about? do you remove all images from many many years past from the photos library, and store separately somewhere outside of the computer? put older content into a separate .photoslibrary? one library for each 5-year period or something? can i daisy chain Mac Mini’s to add additional OS HDs to the environment to allow Time Machine to store backups on separate Hard disks?

    I’m not even going to ask where a RAID system would try to fit into anything like the options above…(unless there is a suitable option?)

    thanks, and thank you for continuing to share your experiences and knowledge with the rest of us…it beats having to go back to school to try to ‘get learned’ any of this new technology stuff. give me back my darkroom and Negs! ( actually, i don’t really miss those either, but they were analog in comparison, at least.)

  38. For a nonprofit that is creating a digital library of video and images, would you recommend a RAID 10? Individual files are TIF between 20,000 and 300,000KB.

    • You can certainly use a raid for this, BUT the raid needs to be backed up. The point of the post is that you can’t count on the redundancy of the RAID to be the backup. You need to back the raid up on another drive, and everything should also be archived someplace else.

  39. Hi Pete,

    Thanks for writing this! It’s really made me rethink my non-existant backup strategy…

    So a few questions.. can I backup 3 external hard drives (each being 1-2TB) to a 5TB SATA drive (connected with a Plugable docking station) using Time Machine on an iMac? Would I always need all external drives connected for it to start backing up or can I have any combination of drives plugged in at any time? Or is it best to partition the 5TB SATA and have each external drive backup to its own partition of about 1TB?

    Also with that 5TB SATA backup drive, can I then run Time Machine to backup that drive to another 5TB SATA drive in order to backup my backups? I worry that’s complicating the process too much!

    Thanks for your time,

  40. Interesting approach. My system is a little more paranoid.

    I have (1) local storage which is very fast; (2) drobo 5N which is my backup of the local storage (2nd copy); (3) several small external drives which each have a couple of years backed up; (4 & 5) : TWO COPIES of everything on bluray data disks. I don’t generally burn blurays more than once every 6 months, but it allows be to be less careful with the older stuff on other storage. What is NOT on the bluray but is on everything else is backups of my edits (lightroom, etc).

  41. By the way (for all) if you DO use RAID (as I am), make sure it is RAID 5, RAID 6, or RAID 1 and not RAID 0 which offers no protection whatsoever. Remember – RAID 0, zero protection. Also in any case this should not be your only copy of the data and I think that was the author’s main point.

  42. And I’m the idiot who did just that! (Had no clue)

    I have a G-RAID 4tb (4th gen) RAID 0 drive. I think the drives are fine but the power cut off as I was uploading files to the cloud as another back up source.

    So it simply won’t power on. I know if I take each drive out of the enclosure they would be worthless in and of themselves. But could I put them in an external dual docking system that supports RAID 0?

    Grateful for any info you might be able to provide….


  43. Pete

    Fantastic post at exactly the level of detail I needed! Thank you for sharing!

    I realise that your setup would have changed in the 4 years since this post was published, so I’m keen to know when you might post an update?


  44. Hello,

    This thread and article are very helpful. Could I use a G-Technology 20T Raid 0 and back it up to another G-Technology 20T Raid or single 10T drive? The reason I ask is that you get the write speed and the safety of a back-up to another drive?

    Thank you,

Leave a Reply

Your email address will not be published. Required fields are marked *

error: Content is protected !!