First Time Machine back-up very slow (est. 1 week)

Question

Level 1

10 points

First Time Machine back-up very slow (est. 1 week)

I have been using Time Machine as a back-up for my 2TB MacBook Pro M1 14". I use a WD external HDD, My Passport Ultra for Mac, 4TB (USB C with a 3.1 cable). Time Machine stopped backing up and my HDD was full. I had manually deleted back up files in the past. Per recommendation of somone in the community I erased the HDD and set it up to be my Time Machine backup. After 3 hours it had backed up 2.3% and estimated 1 week to complete. When the back-ups were working it didn't take long. I stopped the back-up for now. Why is it taking so long? What should I do?

MacBook Pro 14″, macOS 15.3

Posted on Apr 26, 2025 1:38 PM

Reply

Answer 1

Top-ranking reply

D.I. Johnson

Level 7

33,749 points

May 1, 2025 8:39 AM in response to minimejh

minimejh wrote:

I have 77 GB left

Your internal drive would be considered critically low on free space!

Ideally you should maintain 10%-15% of the drive's total capacity as free so that the OS has room to work properly. For a 2 TB drive that equates to a minimum of 200 GB free. If you launch Activity Monitor app and

Your 77 GB free may very well be causing the slowdown in the back up process that you are experiencing.

I suggest you offload at least 150 GB to another external drive and then try running this backup again.

What you can do…

• Empty the Trash in the Dock.

• Empty the trash in the Photos app.

• Delete unused and unneeded application installers from your downloads folder and desktop.

• Reboot your Mac at least weekly.

• Transfer files that you don’t use daily to an external drive and then delete them from the startup drive and empty the trash. Files that take up the most room are movies, images and music.

Reply

Answer 2

Apr 30, 2025 3:08 PM in response to minimejh

I will say that TM is certainly taking its time with this initial backup.

The 2 TB of total storage on your MBP really should not take any more than overnight to copy to a properly operating WD My Passport Ultra 4 TB drive over USB 3.1. I think there has been a glitch of some sort.

If this were my system, I'd stop the backup, erase the external drive and start over.

1) - Remove the backup disk from Time Machine's settings. Time Machine settings on Mac - Apple Support

2) - Then erase the disk:

• Open Disk Utility and click in the Menu bar View > Show All Devices.

• Select the WD device in the sidebar - probably named something like "WD... Media"

• Click Erase, select GUID Scheme, APFS Format, name the drive and click the Erase button.

If TM now asks if you wish to use the disk to backup your Mac, select the affirmative.

3) - If TM doesn't ask, then return to TM settings and add the disk for Time Machine's use.

TM should soon begin a fresh backup attempt to the drive - or you can select "Back Up Now" to start the b/u.

You mentioned in your original post that ❝Time Machine stopped backing up and my HDD was full.❞

So, how much free space do you have on the internal drive?

Reply

Answer 3

Apr 26, 2025 4:17 PM in response to minimejh

Time Machine's first full backup will always take time, sometimes a very long time depending on several factor including total GBs to be backed up, the speed of the drive and connection and whether or not the data is being copied to an encrypted backup drive.

After the first backup is done, all subsequent incremental backups will usually take no more than a few minutes. TM is only copying file that have been changed since the last backup.

So, restart the TM backup and let it do its thing until it's finished. If you encounter failure or error notification from TM, then you may have to erase the drive and start over.

Back up your Mac with Time Machine - Apple Support

Reply