Parallels Desktop No Longer Works with Bootcamp EFI over USB Drive

I'm using what could be considered a "hack" of sorts to use a Bootcamp partition on an external SSD via USB rather than from my Mac's internal drive. This is done in line with the below guide:

https://egpu.io/forums/mac-setup/how-to-install-windows-10-bootcamp-on-an-external-hdd-or-ssd/

It basically involves creating a GPT partition scheme to create a small EFI partition in FAT32, then creating a 2nd partition in NTFS. Windows is installed via DISM on the NTFS partition which basically burns a bootable image of windows to the partition versus going through an installer.

This works fine with native bootcamp if you hold down the option key at boot and select the EFI partition as the boot disk. It also worked fine in parallels desktop 12 -- I would select add new hard drive, select bootcamp, and then choose my external SSD from the list. For this hack to work, I would then need to select both the EFI boot partition and main windows partition and Parallels could load my external windows installation just fine.

Parallels 13, by comparison, does some weird thing where if I try to add the external disk as a bootcamp drive, it claims the .HDD file its trying to create has some read/write error. If I click for more detailed info, it just states "PRL_ERR_DISK_PARTITION_NOT_FOUND" -- an error string that has 0 hits on Google or this site. I've uninstalled any 3rd party apps that could affect filesystem access, including Paragon NTFS.

I cannot collect any other logs at this time as I have since rolled back to parallels desktop 12 which is working fine again with the external drive.

 

Same exact issue happened with me. Frustrating! Spent hours trying to come up with work arounds, including editing the Config files but no dice... Will keep you posted if I find something.

 

I'm experiencing the same problem and have contacted support

 

Just finished the support call, they've gathered information and will need to spend some time analysing more

 

Thanks for the updates. It's good to at least know others are using a similar setup and have actively reported the issue to Parallels. I guess "Windows to Go", although not a super well advertised feature, could be popular among people like me who don't want to waste internal disk space for Bootcamp.

That being said, this is just barely specific enough to be something that possibly escaped dev testing for PD13. Hoping this gets fixed in an update.

 

Hi. I have also problem with loading windows from external drive in parallels 13. As described in https://forum.parallels.com/threads/parallels-13-windows-creator-update-boot-failed.341670/

I have got the following message from Parallels Support:
"We have escalated the issue you reported to the Engineering Team and they are working to address it in one of the future builds of Parallels Desktop for Mac."

 

Can anybody confirm if this is fixed in Parallels 13.1 for them? I didn't see any reference to this bug in the change log. I tied 13.1 myself and am still getting the exact same aforementioned behaviors -- some weird read/write access error when I try to add my external disk as a Boot Camp drive. I also tried selecting "external drive" from the boot settings as another option, but again, the Windows boot logo shows up and hangs indefinitely.

 

I still can't get it working on mine. What's the deal Parallels? Going to leave us hanging?

 

The last correspondence I received for this was:

 

Just to save people the trouble, Parallels Desktop 13.1.1 still has this issue.

 

Can also confirm has the same issue. My solution? I switched to VMWare Fusion and can boot to the external drive with no problem. I happen to like the software a lot more as well - sorry I didn't switch earlier. Too little too late with Parallels. By the way I realize that not everyone will want to drop a license for VMWare Fusion - but for the record, it does work.

 

I tried to update to Parallels Desktop 13 for Mac Update 2 (13.2.0-43213) as the release notes had some interesting items:

• Resolves an issue with the "There is no operating system installed in this virtual machine" message appearing when launching a newly created Boot Camp virtual machine.
• Resolves an issue with Boot Camp virtual machines not booting and stuck on "Trying to boot from SATA drive 1".
• Resolves an issue with not being able to create a Boot Vamp virtual machine on Macs with High Sierra.
• Resolves an issue with not being able to create a Boot Camp virtual machine on 2010 or earlier Macs.
• Resolves an issue with not being able to create a Boot Camp virtual machine on Macs with Fusion Drive.

Unfortunately there's a new error:
Error: PRL_ERR_DISK_INVALID_BLOCKSIZE (0x80021009)
Path: '/Users/Me/Parallels/My Boot Camp 1.pvm/SAMSUNG MZ7LN256HMJP-00000 (disk2).hdd'

This is frustrating as I've paid for this product and can't use 13, when 12 works fine. I bought the product after using the trial as I was happy that it worked but now I can't get the performance boosts and improvements!

 

The issue persists with Parallels 13.2 as the person above noted. There was nothing too promising in the release notes to begin with.

It's been 3 full months now since the issue was reported to their engineering team. I tried VMWare 10 for the heck of it, but was not too happy with it. It seems that has a ton of issues of its own -- eg: A generic "internal error" message whenever trying to start a VM with no other explicit info (they seem aware of this and suggest running the app via Terminal), you have to jump through many more hoops and be comfortable executing CLI commands and modifying raw config files in order to boot windows from an external Bootcamp volume, and VMWare seems to have generally shadier practices where the installer makes undocumented changes to your system that you need to manually undo even after removing the app (eg: it actually modifies and *corrupts* the default $PATH shell argument, essentially breaking the Terminal -- people are extremely mad about that and it has yet to be addressed.)

So granted what a total headache even just touching VMWare was, I guess I will need to use Parallels 12 for the indefinite future.

 

Exact same issue....Following

 

It seems to me that PD 12 is a better than PD 13.

 

Just popping in again to confirm the issue still exists with PD 13.3.1.

Looks like I will keep using PD 12 until compatibility breaks with Windows 10 or the macOS host OS. Currently using the latest Windows 1803 build and macOS 10.13.5 with no issues.