Big Sur external drive backup- not Time Machine

Interested in current best external drive backup practices under Big Sur. I use a 2020 3.6 GHz 10-core i9 Intel iMac at work and use a late 2014 Intel i7 iMac at home. Both machines now on Big Sur, MacOS 11.1
I have been a user of Super Duper forever to schedule back ups to my external drive, but according to the Shirt Pocket blog, Super Duper does not work now under Big Sur. I immediately looked at Carbon Copy Cloner, and from what I can discern, it does work for my machines (not Apple Silicon).
Before I buy CCC, what is recommended as the best software to make a clone of my working drive on some kind of an automatic schedule?
Meanwhile, I have a working Time Machine backup attached- but I make a second copy of my machines twice a week and SD has been great for that purpose.
Thanks for your input.

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Since TimeMachine (which is from the vendor, and should be bullet proof) breaks about every 6 months for me and some other experiences, I have an inherent mistrust of backup software.

Thus, I use:

  • CCC to clone my iMac Pro (Catalina) internal drive to an external SSD once a week.

  • Arq to back up the internal and two externals to my NAS, and also to an external HDD every hour.

  • ChronoSync to backup the internal and two externals to one of two HDDs every 15 days, and I alternate, so the cyan one one time, the red one the next, etc.

  • Backblaze to backup the internal and two externals continuously.

  • For my M1 MBP everything on it is pretty much a duplicate of something on the iMac Pro, so I just use Backblaze. For syncing between them, I use Resilio Sync.


For the longest time Super Duper and CCC have been the two that get recommended.

Apart from a brief foray (probably a free trial) many years ago with Super Duper I have been using CCC for a long time and it has never let me down. Mike Bombich is also very good at communicating any issues and what they’re doing about them or cannot do about them along with workarounds. My current understanding is that CCC does work for M1 Macs including making bootable clones.

As for best practice, I am sure that has been discussed many times over on these forums and elsewhere so would be worth a search. Personally I mostly rely on Time Machine for day to day recovery, but also have a weekly clone via CCC to an attached drive, as well as Backblaze with the 1 year retention option.

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I also have (“basically”) the same question.

I’ve been using Chronosync for the last year (backing up to external drives). Their incremental backups are fast - including bootable backups.

But Big Sur changed lots of things, and now I’m unsure if Chronosync’s bootable backup strategy will still be my best option. (I’m still running Catalina and I’ll only update to Big Sur after finding these answers).

I hope they iron out the process (I really like Chronosync), but AFAIK bootable backups became “a bit more cumbersome to make” (?) - at least for the moment?


  1. What are out best options (for making fast incremental bootable backups on external drives under Big Sur)? Chronosync? CCC? Other apps?

  2. Will any of these solutions allow us also to:
    a. Encrypt the backup?
    b. Send it to a cloud storage solution?

  3. Which cloud storage solution would you recomend? (I saw good comments about Backblaze B2, including price-wise).

(Disclaimer: sorry if some of my questions are too basic - I’m probably the least knowledgeable person in this amazing group - and I learn a lot from your contributions!)

Thank you very much!

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“Backblaze” the computer backup service is USD$5.00 per month (per computer) for as much data as you throw at it including locally attached drives. Things have changed for me now, but I recently topped 5TB backed up from my main Mac.

“Backblaze B2” is a cloud storage system that is indeed cheaper than many competitors like AWS and Google Cloud, but you have to consider how much you store and how much you might download and also how much change there will be over time (there are transaction limits). B2 isn’t designed for backups. To store my 5TB on B2 and never make a single transaction (no further uploads nor downloads) would be USD$25 per month. Restoring 1TB would be an additional $10 or so. This is, they claim, substantially cheaper than the competition, with the nearest being Azure at +276% so nearly four times the price.

Conversely to the data cost, with B2 it doesn’t matter how many computers are involved or where the data is coming from (i.e. networked drives).

B2 can be great, I use it for archives but I consider the cost of everything I put there. There’s a price calculator here.


So, can I think of B2 as a Hard Drive in the cloud where I can just send files without synching? I have about 500 GB of photos and other files that are solely archives. I just want something in the cloud where I could grab a file in the rare event that I would need it. Of course I would have a copy of the archives stored locally. But again, I don’t want these files synched as they are on an external SSD that I don’t keep attached to my Mac Mini. Do you think B2 will meet my needs?

CCC had some early problems making bootable clones under Big Sur but those seem to have been resolved. I use a combination of CCC and TM. I haven’t run into problems with TM in the past few years but prefer CCC when I need to recover stuff. I gave Arq a try but didn’t care for it.

Whatever backup system you use be sure to test it regularly. My philosophy is that an untested backup is not a backup.


You’ve got it exactly. And when I say exactly, it is my RAW photos that form the main part of my content on B2. Years ago I discovered that in my migration from Aperture to Lightroom I had managed to lose 3 whole months worth of photos, but I did not discover this until years later. No backup service or system could help me because everything had long since “aged out”. I was lucky to find an old hard drive backup which was way out of date but included the missing photos. This drove me to set up the archive. I don’t update it often, but I only send files up, and never delete anything there. I often go back and reprocess old photos, but the original RAW files never change* and therefore the archive is sacrosanct.

The other thing I have up there is the complete archive of all the podcasts I made between 2006 and 2012 or so. Both things “I’d really hate to lose” and “don’t change”.

*I actually do occasionally edit keywords which are stored inside the RAW (in fact DNG) files and this gives me a dilemma. From time to time when I am suitably motivated, I very carefully set about updating the files in the archive, but never en masse, only one month at a time and with careful auditing. Still nothing ever gets deleted.


Thank you for your help and for describing your system. Your last paragraph strikes a chord, as I think I"ll be doing likewise in the future. I will set up a b2 account today. Cheers.

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FWIW, I use Panic’s Transmit to do my uploads. It has native support for B2. The Backblaze web site lists “top integrations” which will include some alternatives.

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I’ve been testing b2 most of the day. It does meet my needs. Because I’m a Setapp subscriber, I use Forklift. After you mentioned it, I took a look at the b2 “top integrations” and was pleased to see Forklift on the list. I did have 2 instances where I uploaded a folder that had 150 files and I got a warning that *** file could not be uploaded because of a time out. This happened for 3 files out of 150. I have a fairly fast internet service with an upload speed of about 940. The warning indicated that I could skip or stop, so I skipped. After the upload completed 2 of the 3 files actually had been uploaded. So I re-uploaded the 1 missing file. Should I upload smaller numbers of files at a time? Have you had this happen to you?

On another note, I was happy to see that I could upload/download encrypted dmg files. Wanted to make sure I could store some sensitive files there.

Thanks again for your help.

@GMS Sorry for taking this thread in a slightly different direction.

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I do recall having those sorts of problems a while back, but haven’t in ages. I can’t remember what software I was using at the time. All I can say is in recent times Transmit has been solid, including doing a massive upload just a few weeks ago.

As for file types, it’s just a dumb bucket. Give a bundle of bits a name and it’ll take 'em. Assuming, of course, that it is actually a file. The .dmg files are but .sparsebundles are not, nor .app and some others which are all directories in disguise. You can of course upload the directories but if recovering them they won’t be special any more.

Edit: I had an inkling, and found an old blog post I did. The issues I had were with CyberDuck FTP, so which tool you use may make a difference.


Thanks for all your insights and related discussions. This is a great community.
I saw that Shirt Pocket, Dave Nanian, developer of Super Duper, issued an update about the challenges of making bootable backups in Big Sur. After researching, including looking at CCC and ChronoSync, also great backup apps, it appears to me that the issue is a fundamental one–in Big Sur, Apple has elected to disable the ability to copy the system. The exact reasons are beyond my understanding, but the SuperDuper issues are not unique. All these excellent apps have work arounds–here is the proposed work around for SuperDuper, which was just posted Jan 31, 2021. I am following the detailed instructions as we speak–I am not done with the copying, but the process is moving and I am able to auto schedule regular backups. Bottom line is that one is able to get a backup of all his/her user data. A restore is more involved, but Dave provides directions. I believe this process is the best any of these apps can hope for at this moment. Apple may or may not make changes or allow our old processes to work. Here is the new link: Shirt Pocket Watch
Thank you Dave Nanian and SuperDuper.
Good luck to all. Let us know if this solution works for you too.