MacBook Air unable to read an exFAT HDD

[Chip Boy]

Hello everyone,

I own a 2 TB Toshiba Canvio external hard drive, from their Basics line. It is brand new, in perfect physical state and was bought at a perfectly reputable store. There are almost 700 GB of important data saved into it. The HDD is formatted using the exFAT file system. It works like a charm, flawlessly, when connected to any PC, whether cheap and disposable to state-of-the-art. Disk is always mounted in several seconds, no more than 10.

However, it can take up to 60 minutes to mount when I connect it to my MacBook Air. If the golden hard drive disk icon appears at the end of the tedious process, there's more waiting to do, as reading the folders seems to take ages.

While using Disk Utility this week, I noticed that the partition table in the Toshiba HDD is MBR instead of GUID. I suspect that might be the reason I behind the incredible slowness of the mounting process.

Is there a way to change the partition table and the format of my disk without losing any data? The absurd situation is that I have no space to save those archives on my Mac to create a back-up copy of them. What should I do?

 

[chrfr]

Hello everyone,

I own a 2 TB Toshiba Canvio external hard drive, from their Basics line. It is brand new, in perfect physical state and was bought at a perfectly reputable store. There are almost 700 GB of important data saved into it. The HDD is formatted using the exFAT file system. It works like a charm, flawlessly, when connected to any PC, whether cheap and disposable to state-of-the-art. Disk is always mounted in several seconds, no more than 10.

However, it can take up to 60 minutes to mount when I connect it to my MacBook Air. If the golden hard drive disk icon appears at the end of the tedious process, there's more waiting to do, as reading the folders seems to take ages.

While using Disk Utility this week, I noticed that the partition table in the Toshiba HDD is MBR instead of GUID. I suspect that might be the reason I behind the incredible slowness of the mounting process.

Is there a way to change the partition table and the format of my disk without losing any data? The absurd situation is that I have no space to save those archives on my Mac to create a back-up copy of them. What should I do?

You would need to copy the data somewhere else to reformat the drive. If the disk is never used on Windows, you’re better off formatting it in one of the native Mac formats, either macOS Extended (Journaled) or APFS.
Also, you should not trust a single external drive for your data, especially if it’s important as you say it is. Dropping the disk or breaking the connector can lead to your data becoming completely inaccessible.
I would be concerned that the slow access you’re seeing with this drive is indicative of there being either corruption or a hardware problem– a drive should not take 60 minutes to mount, regardless of format. You might also verify that the cable you’re using is allowing the disk to connect at full USB 3 speed, if your Mac supports USB 3.

 

[Chip Boy]

You would need to copy the data somewhere else to reformat the drive. If the disk is never used on Windows, you’re better off formatting it in one of the native Mac formats, either macOS Extended (Journaled) or APFS.
Also, you should not trust a single external drive for your data, especially if it’s important as you say it is. Dropping the disk or breaking the connector can lead to your data becoming completely inaccessible.
I would be concerned that the slow access you’re seeing with this drive is indicative of there being either corruption or a hardware problem– a drive should not take 60 minutes to mount, regardless of format. You might also verify that the cable you’re using is allowing the disk to connect at full USB 3 speed, if your Mac supports USB 3.

Thank you so much for your answer.

The absurd situation is that I have precious little storage space in my Mac (128 GB), so I could never back up all my data using my own computer. What's worse, the external hard drive just won't mount, even after 60 minutes. If the HDD will not mount, how on earth am I going to copy those files?

Would you, by chance, have any advice on this matter?

 

[Chip Boy]

You would need to copy the data somewhere else to reformat the drive. If the disk is never used on Windows, you’re better off formatting it in one of the native Mac formats, either macOS Extended (Journaled) or APFS.
Also, you should not trust a single external drive for your data, especially if it’s important as you say it is. Dropping the disk or breaking the connector can lead to your data becoming completely inaccessible.
I would be concerned that the slow access you’re seeing with this drive is indicative of there being either corruption or a hardware problem– a drive should not take 60 minutes to mount, regardless of format. You might also verify that the cable you’re using is allowing the disk to connect at full USB 3 speed, if your Mac supports USB 3.

Thanks for the comment on the security of an external hard drive.

What kind of device would be sturdy and safe enough to save and protect almost 1 TB of data (the data being mainly a lot of text files and an awful lot of artsy, fashion and design-related image files that are usually small in size). I will definitely won't be using it for Time Machine or as a bootable device.

Thanks again.

 

[chrfr]

Thanks for the comment on the security of an external hard drive.

What kind of device would be sturdy and safe enough to save and protect almost 1 TB of data (the data being mainly a lot of text files and an awful lot of artsy, fashion and design-related image files that are usually small in size). I will definitely won't be using it for Time Machine or as a bootable device.

Thanks again.

Some sort of cloud service (iCloud/Dropbox/OneDrive) might be your best bet. Otherwise, you just need to have two external drives and keep copies of your data on both. There is no one single place or device that you can securely keep your data. Redundancy is critically important.
If your drive won’t mount, your data may already be lost, unfortunately.

 

[Chip Boy]

Some sort of cloud service (iCloud/Dropbox/OneDrive) might be your best bet. Otherwise, you just need to have two external drives and keep copies of your data on both. There is no one single place or device that you can securely keep your data. Redundancy is critically important.
If your drive won’t mount, your data may already be lost, unfortunately.

It does mount instantly and runs smoothly when connected to a PC, no matter how expensive or cheap the computer is. Even if the disk is formatted using exFAT, whenever I connect it to my MacBook it takes about one hour (60 minutes) in completing the whole process. I will be going tomorrow to the Apple store to see if they can offer me some help and advice.

 

[Chip Boy]

You would need to copy the data somewhere else to reformat the drive. If the disk is never used on Windows, you’re better off formatting it in one of the native Mac formats, either macOS Extended (Journaled) or APFS.
Also, you should not trust a single external drive for your data, especially if it’s important as you say it is. Dropping the disk or breaking the connector can lead to your data becoming completely inaccessible.
I would be concerned that the slow access you’re seeing with this drive is indicative of there being either corruption or a hardware problem– a drive should not take 60 minutes to mount, regardless of format. You might also verify that the cable you’re using is allowing the disk to connect at full USB 3 speed, if your Mac supports USB 3.

The cable I am using is definitely able to connect at USB 3 speed, as is my Toshiba external hard drive.

Do you think that the fact that the Scheme I unwittingly chose when formatting the HDD is Master Boot Record (MBR) might be the ultimate cause of the slow performance?

Thanks again for your help and advice.

 

[Howard2k]

I doubt MBR is the issue. I’ve used MBR drives many times. Can you bypass the dock and use USB-C directly? My guess is that’s the issue.

FWIW I was having a problem with an M.2 NVMe drive in an external enclosure. The drives works great connected to my PS5 but via USB-C to the MBA it was giving me all sorts of problems. I replaced the (apparently weak) supplied cable with a brand new USB-C data cable and it’s been flawless.

I would try to find a new cable of high quality, ideally allowing you to bypass the dock, but mine works perfectly well through the dock or direct since I’ve used the new quality cable.

 

[sgtaylor5]

One other point about exFAT is it isn't a journaling file system, like NTFS on the Windows side or HFS+ or APFS on the macOS side. exFAT is made for large file support on flash drives, that don't have a controller like a hard drive does. Journaling file systems write to the journal first on the disk, then to the disk. If anything untoward happens when writing to the disk, on reboot, the system reads from the journal then fixes the disk. That's my limited understanding of that.

If you can find a PC with enough free disk space and install the proper driver for either HFS+ or APFS (bought from Paragon), then you can transfer the data to a folder on the PC from the Canvio, format the Canvio to either HFS+ or APFS with a GUID partition table, then copy the data back to the Canvio.

Wish I was there, I'd do that for you.