Connecting USB thumb drive is unrelable

Connecting a USB flash drive to Windows VM or Mac host doesn't work reliably. When I insert such a USB drive, sometimes I get the pop-up that asks if I want to connect it to Mac or Windows, sometimes I get nothing. Sometimes it connects to Mac even though I chose Windows. Sometimes it remembers if the last connection was to Windows or Mac, and does it automatically again without asking even though I have "ask me what to do" selected.

I have a bunch of USB thumb drives, and some work more reliably than others. But none are close to 100% reliable. I also have noticed that plugging into a USB port directly on my Mac is more reliable than a port on my USB hub. But still not 100%.

My setup: MacBook Pro 13" mid-2014. MacOS Sierra 10.12 (although this problem has persisted since I started with Mac and Yosemite). Parallels version 11.2.2 (32651) (although this problem has persisted since I started with Parallels at version 10). All my thumb drives are NTFS-formatted in Windows.

It seems that this whole USB-drive-connecting functionality is broken. Maybe it's just me, though. Any advice?

 

To use as storage for both Mac and PC, try this on a Mac:

1. Insert the thumb drive into a Mac.
2. Open Disk Utility.
3. Select the drive itself (and not the partition/volume name.)
4. Chose ERASE
5. Choose "ExFat" for the format (red #1)
6. Choose "Master Boot Record" for the sheme (red #2)
7. Click Erase.

Here's the sheet window that appears when you choose "Erase".

 

Thank you Jeremy for taking time to reply with your ExFAT suggestion. I grabbed three thumb drives at random, formatted them ExFAT per your instructions, and I will test them for reliability.

(Also, I like that ExFAT is write-compatible on both Windows and macOS. I hadn't realized that about ExFAT - I guess I haven't been paying attention. Although Parallels insists, when I plug in an ExFAT drive, that it's Read Only on the Mac side. But Parallels is wrong. I can write to an ExFAT drive just fine in both Windows and Mac.)

 

I've been using my ExFAT-formatted USB thumb drives since my post above, and I'm sorry to report that my issues (described in the first paragraph of the first post in this thread) continue just as before.
In addition, I've upgraded to the latest version of Parallels, 12.1.1 (41491), also to no avail.

 

Hi Phil,

I think there are 3-issues:

1. disk format that can be used for both Mac and PC; and
2. USB generation (1, 2, 3.0, 3.1) of thumb drive must match usb generation your computer supports; and
3. which operating system (Mac or Virtual Machine) connects to the USB thumb drive.

Issue #1 -- The ExFat with Master Boot Record works with both platforms: Mac and Windows.

Issue #2 -- Make sure the thumb drive's generation (USB 1, 2, 3, or 3.1) matches the USB generation your computer supports.

Issue #3 -- Have you tried the SmartMount option? The documentation says, "Using SmartMount, you can set Parallels Desktop to automatically mount storage devices and
volumes to Windows. That way, you can access the contents from both Mac OS X and Windows."

See "Share External Storage Devices and Volumes".

 

Me too, I've been using Parallels since 2007 and the only problem I've had is last week. Found out I cannot log into my Apple ID with any OS X virtual machine (I used those for legacy software). It's an open tech issue, coupled with the error from Apple saying this computer/device cannot be verified.
Parallels is normally faultless, currently have Win XP, Win 7 Pro, 10 Pro and Linux Mint 19.0 available as well as most OS X virtual machines (all of which I keep on an external USB drive).