Can't use disk as time machine for encrypted back up.

Question

Level 1

6 points

Can't use disk as time machine for encrypted back up.

Hi,

I am trying to make encrypted backups using Time machine.

If I mount my external drive, I got a message prompting me to use it for Time Machine backups, as none was configured. There was no option to encrypt the disk. I set it up and after a while it started backing up, but then I got a message saying that it was backing up an encrypted disk to an unencrypted one. I saw that in System Preferences -> Time Machine -> Select Backup Disk, there was an option to encrypt the disk so I figured I needed to do it this way. I cancelled the backup and then removed the Disk in System Preferences -> Time Machine -> Select Backup Disk. But upon trying to add it by going to the same place, the disk is not showing there.

Clearly the disk is OK to use as a backup as Time Machine started backing up to it, so why can't I see it in the list of Available disks?

Thanks,

Mark

MacBook Pro Retina

Posted on Jan 20, 2019 4:36 AM

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Answer 1

dialabrain

Level 10

136,079 points

Jan 20, 2019 8:46 AM in response to MarkJFisher

Okay well never use software included with drives.

Make sure "Show All Devices" is selected in "View". Then select the top level of the external drive and choose "Erase".

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Answer 2

dialabrain

Level 10

136,079 points

Jan 20, 2019 8:10 AM in response to MarkJFisher

Make sure the partition map scheme is GUID.

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Answer 3

BDAqua

Level 10

250,253 points

Jan 20, 2019 8:48 AM in response to MarkJFisher

I think you need to uncheck ignore permissions.

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Answer 4

BDAqua

Level 10

250,253 points

Jan 20, 2019 7:00 AM in response to MarkJFisher

What Format is it now? Did it maybe get converted to APFS?

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Answer 5

MarkJFisher Author

Level 1

6 points

Jan 20, 2019 7:57 AM in response to MarkJFisher

The disk is partitioned, if that makes a difference. The partition that I'm trying to back up to is Mac OS Extended (Journaled) and the other one is exFAT.

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Answer 6

MarkJFisher Author

Level 1

6 points

Jan 20, 2019 8:29 AM in response to BDAqua

It says "You have custom access", then "Read and Write" for me and staff, "Read only" for "everyone" and "Ignore ownership on this volume" is checked.

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Answer 7

dialabrain

Level 10

136,079 points

Jan 20, 2019 8:46 AM in response to MarkJFisher

You're welcome.

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Answer 8

MarkJFisher Author

Level 1

6 points

Jan 20, 2019 8:32 AM in response to dialabrain

I am not sure how to find that out, though I am trying to unpartition and repartition, to see if there is an option to ensure the map scheme is GUID. I have erased both partitions and formatted as Mac OS Extended (Journaled). However the Partition button at the top of Disk Utility is greyed out for both partitions. I believe I need to click this button to remove the partition?

I created the partition with the LaCie setup which came on the hard disk.

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Answer 9

MarkJFisher Author

Level 1

6 points

Jan 20, 2019 8:43 AM in response to dialabrain

Thanks, that has solved my problem. I was able to partition using the GUID partition map scheme. Both partitions are now showing as available, and this time the automatic prompt even gave me the option to encrypt. I have learnt my lesson about using included software now.

Thank you!

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