Formatting flash-drives always fails the first time

[Tesla1856]

For some reason, I have to erase and format all my flash-drives twice, because it fails the first time.

It happens on all USB ports in back of Mac-Mini and with different Lexar and Verbatim USB flash-drives. Seems to always fail the first time, then completes the second time. They format on my other Windows machine fine.

I don't recall this happening before I upgraded from El Capitan to Sierra a week or so ago. At first, I thought maybe my USB ports were going bad all of a sudden. However, the ports work fine for other things.

I found these in Google:
https://apple.stackexchange.com/que...ternal-disk-twice-first-time-will-always-fail

and

https://discussions.apple.com/thread/7816322?start=15&tstart=0

I guess it's good to see I'm not the only one having a problem with it. At least I know my MacMini is likely not broken. I'm guessing someone has officially reported it, but interesting to see it's still broken on v10.12.6 . Maybe it's only happening on certain machines?

Is anyone else here having this problem? Is there a known work-around?

 

[Tesla1856]

A friend with an older MacPro Tower says it works fine for him. He is also running macOS v10.12.6.

Sounds like "Disk-Utility Commands must be repeated twice to work properly" Bug only affects certain models (apparently, a common occurrence with various bugs).
[doublepost=1501181252][/doublepost]Is Apple getting messy and careless with macOS? v10.12.6 isn't beta, but instead final-released/stable.

I found it written about here also:

https://eclecticlight.co/2017/07/21/known-bugs-in-macos-sierra-10-12-6-an-incomplete-summary/

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Disk Utility – commands fail

Various problems can be encountered in Disk Utility. This include an apparent inability to mount volumes, failure to partition disks, and sometimes reporting errors when trying to perform a command the first time, but performing them normally when asked a second time.

These are sporadic, and appear unpredictable.

(Thanks to Michael Tsai for reminding me of these.)

------------------------
[doublepost=1501184229][/doublepost]Kinda scary to me to see problems with core-disk functions.

However, it appears that Disk Utility might just be aborting before waiting long enough for the commands to finish (like Mount/un-Mount, etc.) ... depending on current status of disk being worked on.

 

[AlexH]

I'm glad I found this thread, because I'm encountering the same issue. It's frustrating. I was cleaning out some old USB thumb drives, reformatting them, and every one of them would fail the first go. Then yesterday I erased/encrypted an external 128GB SSD, and same thing, failed the first time, but worked the second. I even booted into Safe Mode and went through the whole process again, but it continued to fail the first attempt in Safe Mode too.

Definitely a Sierra bug, my El Capitan install works every time the first time around. Hopefully this will either get patched or resolved in High Sierra.

 

[Tesla1856]

1. Definitely a Sierra bug, my El Capitan install works every time the first time around.

2. Hopefully this will either get patched or resolved in High Sierra.

1. Thanks for confirming.

2. Agreed. From the looks of my URLs, I'm hoping it got reported.

What Macs do you have, with what OS on each?

 

[AlexH]

1. Thanks for confirming.

2. Agreed. From the looks of my URLs, I hoping it got reported.

What Macs do you have, with what OS on each?

Two 15" Mid 2014 MacBook Pros in my house. El Capitan on one, Sierra on the other.

 

[stillcrazyman]

I have a Late 2012 iMac 32GB, 1TB SSD - running 10.12.6. I noticed this same behavior
yesterday with three different flash drives. First attempt doesn't work, second try does. No reason or error codes reported.

Hope that gets sorted soon.

 

[Ethosik]

I always eject my drive through Disk Utility before I erase it. I have no issues when I do that, it works the first time.

 

[AlexH]

I always eject my drive through Disk Utility before I erase it. I have no issues when I do that, it works the first time.

Still doesn't work for me. Out of curiosity, what model Mac are you using?

 

[Ethosik]

Still doesn't work for me. Out of curiosity, what model Mac are you using?

Last time I used a flash drive was on my 2016 Macbook Pro.

 

[AlexH]

Last time I used a flash drive was on my 2016 Macbook Pro.

I wonder if it's some sort of chipset issue or other random motherboard quirk. I'm using a 2014 MacBook Pro. Folks with newer hardware don't seem to have the issue as often. I've got a 2017 5K iMac on the way, I'll do some testing and post the results when it arrives.

 

[JacekSD]

I wonder if it's some sort of chipset issue or other random motherboard quirk. I'm using a 2014 MacBook Pro. Folks with newer hardware don't seem to have the issue as often. I've got a 2017 5K iMac on the way, I'll do some testing and post the results when it arrives.

It failed on my 2017 5K iMac, but I don't remember if I ejected it first or not.

 

[AlexH]

I just erased and formatted a new external SSD on a brand new 2017 27" iMac, and it worked flawlessly. I was a little surprised, actually. Might be a fluke, or it might be a bug specific to certain models.

 

[BLUEDOG314]

I have experienced this as well on three devices running 10.12.6. An early 2011 MBP 13", 2016 rMB, and a 2017 MBP 15". Each time details in Disk Utility say failed to unmount disk or something along those lines. I use terminal for all my partitioning anyway, and will occasionally be a little extra and zero the partition map as well. That works fine, but its gotta be some kind of bug.

 

[zorinlynx]

Sometimes it fails to unmount the disk for some reason, and you can try again and it will. This will cause the problems described in this thread.

I suspect something is using the filesystem in that instance (most likely Spotlight) and it doesn't release it in time.

 

[Buggyflayer]

I have 2 partitions on a Transcend JetDrive Lite which is permanently mounted in the SD slot of my 2012 Air. Wanted to clear one partition to offload from my internal drive to leave room to update to Sierra but then had the failed to unmount error & was wondering if there was an issue with the drive until repeated attempts yielded a format.

Good to read that its a bug others are seeing & not just my system however my anomaly is that the issue happened while using El Capitan 10.11.6

 

[mkleck]

The same thing happens on my Late 2017 imac and rMBP runing macOS Sierra. Super annoying.

Specs of the imac
iMac (Retina 5K, 27-inch, 2017)
4.2 GHz Intel Core i7
64 GB 2400 MHz DDR4
Radeon Pro 580 8192 MB
500GB SSD

 

[AlexH]

The same thing happens on my Late 2017 imac and rMBP runing macOS Sierra. Super annoying.

Specs of the imac
iMac (Retina 5K, 27-inch, 2017)
4.2 GHz Intel Core i7
64 GB 2400 MHz DDR4
Radeon Pro 580 8192 MB
500GB SSD

I have the same machine, and it worked on my first attempt (see my previous post), but it failed again a few days ago. My theory about it being specific to certain hardware seems to be incorrect.