# TIME MACHINE SET UP on new disc

**URL:** <https://forums.sandisk.com/t/time-machine-set-up-on-new-disc/304974>\
**Category:** External SSD for macOS\
**Created:** [January 29, 2022, 6:07pm UTC](https://forums.sandisk.com/t/time-machine-set-up-on-new-disc/304974 "2022-01-29T18:07:19Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![JADE\_1](https://avatars.discourse-cdn.com/v4/letter/j/f4b2a3/32.png) [@JADE\_1](https://forums.sandisk.com/u/JADE_1)\
**Post date:** [January 29, 2022, 6:07pm UTC](https://forums.sandisk.com/t/time-machine-set-up-on-new-disc/304974/1 "2022-01-29T18:07:19Z")

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Just purchased a WDBA24OOBBL 4TB portable disc to use for time machine backup of a Mac mini M! .  
I’m not tech savvy and having managed to load the software it is now asking me to erase the disc before it will work with Time M . Presumably it wants to get rid of WD software???

Installation info seems impossible to find on the web site.

At the same time I purchased a 2tb disk to back up a laptop using O/S Catalina and that has been ok without asking me to erase the disc.

What’s going on?

jd

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**Author:** ![Jose2020](https://avatars.discourse-cdn.com/v4/letter/j/c37758/32.png) [@Jose2020](https://forums.sandisk.com/u/Jose2020)\
**Post date:** [January 31, 2022, 4:56am UTC](https://forums.sandisk.com/t/time-machine-set-up-on-new-disc/304974/2 "2022-01-31T04:56:08Z")

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Many mac systems support Time Machine on APFS formatted drives only. There might be chances that your drive is in HFS+ format, that’s why it is asking you to erase or reformat the drive in order to create a time machine.

As, if you want to shift a drive from HFS+ to APFS, you have to reformat the drive, and that erases all the Time Machine backups. Because of the structural differences, you can’t just copy from HFS+ to APFS, either.

Further, you can also check the below link for more details:

> **[macOS Big Sur: Using APFS on a Time Machine drive has some catches](https://www.macworld.com/article/234913/macos-big-sur-supports-time-machine-on-apfs-formatted-drives-but-there-are-a-few-catches.html)**
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> The updated macOS finally allows you to use a drive formatted with Appleu2019s not-very-new APFS filesystem as a Time Machine destination.

Hope it helps!

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**Author:** ![JADE\_1](https://avatars.discourse-cdn.com/v4/letter/j/f4b2a3/32.png) [@JADE\_1](https://forums.sandisk.com/u/JADE_1)\
**Post date:** [February 2, 2022, 3:47pm UTC](https://forums.sandisk.com/t/time-machine-set-up-on-new-disc/304974/3 "2022-02-02T15:47:48Z")

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Thanks for the replies. Erasing seems to have worked.  
The WD files/folders have disappeared.