Resolved Disk Utility creating wrong partition sizes

[milaround]

Pretty straightforward problem:

1. Partition an external 4TB disk into 2TB/1TB/1TB

2. Get totally screwed up partition sizes:

What is going on, and how do I create the partition sizes that I want?
10.11.1 all software updated to latest.
Thanks for any help!

 

[Shirasaki]

I remember when I was creating partitions on one of my new hard disks, I saw correct 1.5TB and 500GB, not any weird number. But I did this under an early beta of El Capitan 11.10.0.
Apple screws this up in official software?

 

[milaround]

It appears I have solved the issue; Here's the rest of my journey for anyone else who may have this issue:


Starting from the above screen shot:

Tried to re-partition the existing partitions into a single 4TB
Failed with error:

Erased main drive, yielded a 4TB partition. Partition map showed a non-removable 0kb "Untitled" partition.

Proceeded to partition as 2/1/1TB (Note the odd-looking graph)

The "Untitled" partition is gone, and Disk Utility shows the partitions correctly on the graph, but is missing a partition on the list.

Quitting/Restarting Disk Utility now shows the previously missing partition. All seems well from this point.

Seems like buggy native software. Sad to see... I will report back if something goes wrong.

 

[ataractic]

It appears I have solved the issue; Here's the rest of my journey for anyone else who may have this issue:


Starting from the above screen shot:

Tried to re-partition the existing partitions into a single 4TB
Failed with error:

Erased main drive, yielded a 4TB partition. Partition map showed a non-removable 0kb "Untitled" partition.

Proceeded to partition as 2/1/1TB (Note the odd-looking graph)

The "Untitled" partition is gone, and Disk Utility shows the partitions correctly on the graph, but is missing a partition on the list.

Quitting/Restarting Disk Utility now shows the previously missing partition. All seems well from this point.

Seems like buggy native software. Sad to see... I will report back if something goes wrong.

[doublepost=1507821473][/doublepost]I've seen similar issues repeatedly when trying to partition disks using disk utility in El Capitan. I'm not sure when this bug was introduced, but it is very concerning to see a something as essential as disk utility apparently not being tested enough before release. I guess the focus is shifting more and more to shiny new features rather than the core OS. I use terminal to partition my disks now. Sad indeed...

 

[McGone]

Bug is still around in 2019 with High Sierra. I had same result as milaround with 2TB partitioning request of 500GB/750GB/750GB producing partitions of 500GB/1250GB/250GB. But, the solution to quit Disk Utility and restart it did not change anything. The solution that I found was to repeat the erase then, add one partition at a time, i.e. partition 500GB/1500GB then add the third partition by splitting the second partition in to 750GB/750GB. This was on a Seagate Plus drive. Weird since earlier in the day the same three partition configuration was correctly created on a 2TB Silicon Power drive in a single step.