Resolved Problems with partition sizes in Disk Utility?

[rhimbo]

Hi folks,

I'm trying to repartition an external 3TB drive. Currently I have

1. 1 TB partition, 663 MB used space (basically not used, I think the 663 MB is the amount used in formatting)
2. 2 TB partition, 853 GB used space (TimeMachine back ups)

I'd like to create 3 1-TB partitions. So I do this:

1. Select the 2 TB partition in the circle graphic in Disk Utility
2. Click the "+" to add a new partition
3. Specify a size of 1 TB

Then Disk Utility goes off for 45 minutes. In the end it fails with a message that the partition cannot be resized and suggests reducing the size of the partition I'm trying to create.

I'm wondering why it's failing. I'm wondering if the problem is the TiB versus TB issue. I'm going to try again, this time specifying an appropriately smaller size. But I'm wondering why it failed given that the size recognized by Disk Utility is in fact 3 TB. So, shouldn't the size calculation be fine if I also specify my partition sizes in TB?

I've attached a screen grab of the Disk Utility window.

Thanks,

 

[joevt]

I guess Drive Utility is having trouble squeezing the 853 GB used space of the 2 TB partition into a 1 TB partition.

I've never used TimeMachine back ups before. Can you move the Time Machine backups manually to the existing 1 TB partition, then erase the 2 TB partition and add a new 1 TB partition? I guess you need to find out if TimeMachine will allow moving backups that way.

 

[rhimbo]

Ok, thanks. I'll try that. I think there are lots of bugs in these utilities and even in the OS. I noticed that this particular drive is frequently spinning even when there should not be any access read or write to that drive.

I have a second drive, identical, that is never spinning unless there is some access to the drive that I can explain. So, I wonder if there is some issue with the way macOS sees the drive or with the state of the file system or perhaps even the drive itself. It seems to be working fine; I can access the backups.

I'll try what you suggest first. If that doesn't work, I'll next try to make smaller partitions, say 900 GB. I'll update this thread in case anyone is interested....

 

[rhimbo]

The solution was to specify only ExFAT for all partitions on the drive. Apparently you cannot mix Apple file system types with non-Apple types such as ExFAT for partitions on the same physical drive.