Time Machine backup with 64GB flashdrive

[circatee]

Advance warning, this might be new Mac OS user error.

My MBA has been setup as new, with Big Sur as the OS. I am still in the learning phase, and wanted to test Time Machine.
During the setup of Time Machine, I connected a 64GB USB (3.0) flash drive. And, kept getting an error with Time Machine, "Unable to unmount drive"...

Is the above error due to my drive being smaller than the overall drive of the MBA?
Currently, there is NO data on my MBA, merely the OS. I have not even added my Apple ID account to the unit yet. So, no photos, iMessage, etcetera, etcetera.

Weird, no?


MBA Specs:
MacBook Air 13" Early 2015
Memory: 8GB
Processor: 1.6GHz dual
GPU: Intel HD Graphics 6000 1536MB
Storage: 251GB flash storage
OS: Big Sur

 

[xboxbml]

Advance warning, this might be new Mac OS user error.

My MBA has been setup as new, with Big Sur as the OS. I am still in the learning phase, and wanted to test Time Machine.
During the setup of Time Machine, I connected a 64GB USB (3.0) flash drive. And, kept getting an error with Time Machine, "Unable to unmount drive"...

Is the above error due to my drive being smaller than the overall drive of the MBA?
Currently, there is NO data on my MBA, merely the OS. I have not even added my Apple ID account to the unit yet. So, no photos, iMessage, etcetera, etcetera.

Weird, no?


MBA Specs:
MacBook Air 13" Early 2015
Memory: 8GB
Processor: 1.6GHz dual
GPU: Intel HD Graphics 6000 1536MB
Storage: 251GB flash storage
OS: Big Sur

It's probably not formatted correctly...

 

[circatee]

I formatted it as "Mac OS Extended (Journaled)".
Is that incorrect?

 

[xboxbml]

I formatted it as "Mac OS Extended (Journaled)".
Is that incorrect?

Yeah, should be.. interesting..

 

[HDFan]

Is the above error due to my drive being smaller than the overall drive of the MBA?

Probably not, but run a test. In the Time Machine preference panel choose options, and select only one small directory to backup, excluding all others. Then run backup to see what happens.

Be sure not to rely on TM as your only backup.

 

[circatee]

Probably not, but run a test. In the Time Machine preference panel choose options, and select only one small directory to backup, excluding all others. Then run backup to see what happens.

Be sure not to rely on TM as your only backup.

Thanks for the response. The issue is, Time Machine does not even finish the setup process, to thus use said flash drive.
Hence, I was curious about the size of the flash drive (64GB), considering the MBA has a max drive size of 251GB flash storage...

 

[HDFan]

Time Machine does not even finish the setup process,

Not sure what you are saying. You select the drive in Time Machine preferences and select the content which you want to back up. They you wait for the backup to start, or you start it manually.

The setup process is selecting the disk and setting the options. It is now in the backup state. It makes the first full backup, and then subsequently updates the backup as necessary.

Where is it failing?

 

[circatee]

Not sure what you are saying. You select the drive in Time Machine preferences and select the content which you want to back up. They you wait for the backup to start, or you start it manually.

The setup process is selecting the disk and setting the options. It is now in the backup state. It makes the first full backup, and then subsequently updates the backup as necessary.

Where is it failing?

Sorry if I was not clear.

To confirm, during the 'setup' process (first time ever using TM), one has to choose the backup drive of choice.
In doing so, the system configures said drive (does something to it). During said process, is when it fails. Thus, I cannot even 'select' the drive I wish to use for backups.

Does that help?

PS: I have tried to thumb/flash drives (32GB and 64GB). Nothing larger around me at the moment...

 

[HDFan]

Is the above error due to my drive being smaller than the overall drive of the MBA?

Nope. I just setup a 128 GB USB stick and it immediately went into the list of TM disks even though my backup selection is much larger than the stick.

In doing so, the system configures said drive (does something to it).

So the problem occurs when after you select the drive to be added to TM preferences? It is never added? I am unaware of any configuration that occurs when the disk is added, think it is just added to the list of active TM disks. Maybe TM for some reason can't open the stick.

You are able to see the stick in the finder, copy from/to the stick?

 

[circatee]

Nope. I just setup a 128 GB USB stick and it immediately went into the list of TM disks even though my backup selection is much larger than the stick.



So the problem occurs when after you select the drive to be added to TM preferences? It is never added? I am unaware of any configuration that occurs when the disk is added, think it is just added to the list of active TM disks. Maybe TM for some reason can't open the stick.

You are able to see the stick in the finder, copy from/to the stick?

Thanks for the response, certainly appreciated.

Merely trying to add ANY flash drive (32GB, and 2, 64GB flash drives - all PNY), to Time Machine.
I select the drive (I can see it on the Mac), and it starts the process to see the drive in Time Machine, then the error pops up, "Couldn't unmount disk". In addition, after this error, I then see TWO of the drives listed on my Desktop.

Weird...

 

[circatee]

Update:

I formatted the flash drive again, and made sure I used "macOS Extended Journaled"
Once that completed, a message showed in the Notification area, stating, "You can use your new drive for Time Machine. Do you want to set it up...?" (something like that).

Start to process the new drive, and the SAME error as above came up...

 

[chabig]

First, using a flash drive for Time Machine is a bad idea because they aren't robust. But if you're just testing it's ok.

Second, Time Machine in Big Sur is going to reformat the drive to AFPS Case Sensitive. You might just try formatting it that way yourself so it doesn't have to unmount the disk to do so.

 

[circatee]

First, using a flash drive for Time Machine is a bad idea because they aren't robust. But if you're just testing it's ok.

Second, Time Machine in Big Sur is going to reformat the drive to AFPS Case Sensitive. You might just try formatting it that way yourself so it doesn't have to unmount the disk to do so.

Yes, this is purely for testing and learning how the process works (prior to purchasing a decent storage device).

Trying your process now. I was under the impression that AFPS did not work with Time Machine. Thanks!

 

[chabig]

I was under the impression that AFPS did not work with Time Machine.

That was previously true. Big Sur is the first macOS to use AFPS for Time Machine.

 

[Mellofello808]

Ideally you want your TM drive to be at least as big as the internal drive.

 

[circatee]

Ideally you want your TM drive to be at least as big as the internal drive.

Hmm, are you thinking that is why I am experiencing the issues that I am?
Maybe at the weekend, I will purchase a 256GB or higher, storage device...

 

[deeddawg]

Yes, this is purely for testing and learning how the process works (prior to purchasing a decent storage device).

Trying your process now. I was under the impression that AFPS did not work with Time Machine. Thanks!

Hmm, are you thinking that is why I am experiencing the issues that I am?
Maybe at the weekend, I will purchase a 256GB or higher, storage device...

Maybe just me, but I wouldn't waste my time trying to make something work that I'll never actually use.

IMHO: ideally you want your TimeMachine backup device to be at least 2x the amount of storage you use, if not 2x the size of the system drive. Remember that TM is a versioned backup, so the more storage you give it the further "back in time" you can go. This becomes handy in the event something becomes corrupted internally yet still exists as a file. That corrupted version gets backed up. With versioning you can potentially go back and recover the pre-corruption version. Without versioning you're screwed.

Your time machine storage device needn't be super fast though. The common and inexpensive external hard drives in the 2TB range for $60 will do fine.

Also be thinking through what your flood/fire/robbery scenario is in which both your computer and your backup drive are destroyed/stolen. I presently use iDrive cloud backup, but will revisit during any potential holiday sales next week and beyond.

10 Best Mac Backup Software Picks 2025: Protect Your Mac

Apple’s Time Machine is an adequate backup. However, if you need something more, check out our list of the best Mac backup software.

www.cloudwards.net

How to back up your Mac 2022

One of the most important things you should be doing with your Mac is backing up all of its data. Here are some of our favorite solutions for backing up your most important files, should anything ever

www.imore.com

 

[circatee]

Maybe just me, but I wouldn't waste my time trying to make something work that I'll never actually use.

IMHO: ideally you want your TimeMachine backup device to be at least 2x the amount of storage you use, if not 2x the size of the system drive. Remember that TM is a versioned backup, so the more storage you give it the further "back in time" you can go. This becomes handy in the event something becomes corrupted internally yet still exists as a file. That corrupted version gets backed up. With versioning you can potentially go back and recover the pre-corruption version. Without versioning you're screwed.

Your time machine storage device needn't be super fast though. The common and inexpensive external hard drives in the 2TB range for $60 will do fine.

Also be thinking through what your flood/fire/robbery scenario is in which both your computer and your backup drive are destroyed/stolen. I presently use iDrive cloud backup, but will revisit during any potential holiday sales next week and beyond.

10 Best Mac Backup Software Picks 2025: Protect Your Mac

Apple’s Time Machine is an adequate backup. However, if you need something more, check out our list of the best Mac backup software.

www.cloudwards.net

How to back up your Mac 2022

One of the most important things you should be doing with your Mac is backing up all of its data. Here are some of our favorite solutions for backing up your most important files, should anything ever

www.imore.com

Very good information. Thanks for taking the time to share...

Again, my current issue with Time Machine, was merely from a testing/learning, perspective. Alas, I do plan on a Cloud storage. This weekend I will obtain some local storage, and go from there. Actually, you know, I need to check my 'IT Box of stuff'. I might even have 500GB SSD drive and USB cable

 

[circatee]

Update:
Today, while searching for a hard drive enclosure, I was reading a review. During the review, the individual had a MBA 2015, and was experiencing issues with the drive and drive speeds via USB. He stated that if you turn off Bluetooth, then connect the drive, the issue and speeds resolved themselves.

So, with that in mind, I turned off Bluetooth, connected my PNY 64GB flash drive. I then formatted it accordingly.
Guess what...?

...the bloody drive is doing a Time Machine backup, as we speak. First one, and it will take 30 minutes.
Speechless.

Of course, having the Bluetooth off is simply weird. Even more so, because I cannot use my MX Master during said time

 

[xboxbml]

Update:
Today, while searching for a hard drive enclosure, I was reading a review. During the review, the individual had a MBA 2015, and was experiencing issues with the drive and drive speeds via USB. He stated that if you turn off Bluetooth, then connect the drive, the issue and speeds resolved themselves.

So, with that in mind, I turned off Bluetooth, connected my PNY 64GB flash drive. I then formatted it accordingly.
Guess what...?

...the bloody drive is doing a Time Machine backup, as we speak. First one, and it will take 30 minutes.
Speechless.

Of course, having the Bluetooth off is simply weird. Even more so, because I cannot use my MX Master during said time

Wow... Yeah that is very interesting.. I've turned off my BT for a while now, as it was one of the reasons Catalina on my machine was sucking battery overnight.. Perhaps BT and USB use the same data line somewhere and that's why?.. I dunno.. Good catch though! If you could post the review link where you found that, that would be helpful. Thanks.

 

[circatee]

Wow... Yeah that is very interesting.. I've turned off my BT for a while now, as it was one of the reasons Catalina on my machine was sucking battery overnight.. Perhaps BT and USB use the same data line somewhere and that's why?.. I dunno.. Good catch though! If you could post the review link where you found that, that would be helpful. Thanks.

This is the link.

Additional Update:
Time Machine's first backup completed! I do wonder if the USB port was not able to draw enough power, with Bluetooth being on. Alas, merely guessing here. Even more so, since the steps I followed are exactly the same as when I started this thread...

 

[xboxbml]

This is the link.

View attachment 1681173

Additional Update:
Time Machine's first backup completed! I do wonder if the USB port was not able to draw enough power, with Bluetooth being on. Alas, merely guessing here. Even more so, since the steps I followed are exactly the same as when I started this thread...

Hmm.. yes, I guess that could be another factor, however, I've never had an issue with my 1 or 2tb USB spinning drives with BT enabled..