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atakacs
Enthusiast
Enthusiast

Connected USB drive seen as read only under Windows 7

Hello

I'm having an issue mapping external USB drives into a Windows 7 VM. For some reason the drive is recognized but appears as read only.

I have tried both USB2 and USB3 (with Intel drivers) virtual adapter and I have the same problem in both cases.

Interestingly it works fine in a Win10 VM so I guess it is somehow a factor of using Win7 - that being said I have no idea who to handle this one. This is Fusion 8.5.6 with Win 7/32 fully patched.

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RickShu
VMware Employee
VMware Employee

Hi atakacs,

Some people have had success running chkdsk from an Administrator Command prompt, try a command like:

chkdsk /f E:    (where E: is the USB drive)

Would you please give it a try?

Attention: Make sure you have backup all the data in your USB drive before you run the command.

Regards,

-Rick

atakacs
Enthusiast
Enthusiast

thanks for the suggestion. Here is what I get...

Microsoft Windows [Version 6.1.7601]

Copyright (c) 2009 Microsoft Corporation.  All rights reserved.

C:\Users\admin>chkdsk e:

The type of the file system is NTFS.

Volume label is SSD.

WARNING!  F parameter not specified.

Running CHKDSK in read-only mode.

CHKDSK is verifying files (stage 1 of 3)...

  71 file records processed.

File verification completed.

  0 large file records processed.

  0 bad file records processed.

  0 EA records processed.

  0 reparse records processed.

CHKDSK is verifying indexes (stage 2 of 3)...

  99 index entries processed.

Index verification completed.

  0 unindexed files scanned.

  0 unindexed files recovered.

CHKDSK is verifying security descriptors (stage 3 of 3)...

  71 file SDs/SIDs processed.

Security descriptor verification completed.

  14 data files processed.

Windows has checked the file system and found no problems.

244207615 KB total disk space.

104906816 KB in 12 files.

        16 KB in 16 indexes.

         0 KB in bad sectors.

     73487 KB in use by the system.

     65536 KB occupied by the log file.

139227296 KB available on disk.

      4096 bytes in each allocation unit.

  61051903 total allocation units on disk.

  34806824 allocation units available on disk.

C:\Users\admin>chkdsk e: /f

The type of the file system is NTFS.

Windows cannot run disk checking on this volume because it is write protected.

C:\Users\admin>

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bluefirestorm
Champion
Champion

atakacs,

Sorry I don't have any solution for you but just to let you know something similar occurred to me before and may not have to do with VM.

Many years ago, I had an external USB hard disk that also appeared as read-only to a Windows Vista Business x64 laptop (shows how long ago it was, I think it was mid to late 2009 when I bought both laptop and USB 2.0 HDD within weeks of each other). The same USB disk worked fine on other systems that I had (a laptop with 32-bit Windows XP Professional and a desktop with 32-bit Windows XP Professional). All other USB 2.0 disks and USB 2.0 thumb drives worked fine with the same laptop with Windows Vista Business x64.

The problem of this hard disk appearing as read-only to this laptop went away when the Vista x64 Business was upgraded to Windows 7 Professional.

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atakacs
Enthusiast
Enthusiast

Thanks

i can now confirm that the issue has to do with USB3.

If I connect an USB2 disk to the VM everything works as expected.

If I connect an UBS3 disk it is seen a "read only" by the guest OS - regardless of the use of USB2 or USB3 virtual adapter.

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ColoradoMarmot
Champion
Champion

Windows 7 doesn't natively support USB 3, so that's very likely the problem. I recall some suggestions to use third-party USB 3 drivers, but don't have links to those posts in the forum.

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wila
Immortal
Immortal

Hi,

FWIW, here are my notes on the subject. Note that the 3rd party driver is from intel and is supported by VMware for Fusion 8 and up.

Unfortunately Windows 7 itself does not come with USB3 support (this is sometimes referenced as windows 7 not having an inbox driver for USB3).


In order to use a USB3 device under VMware Fusion you have the following options:


- Use an operating system with USB3 support (eg. Windows 8.x or similar)


- Use a USB2 hub or USB2 cable between your computer and the USB3 device you want to use to downgrade the USB3 interface to USB2


- Connect to a USB2 connector on your computer if your computer provides such a connector.


- You can try setting the USB compatibility under menu Virtual Machine -> Settings -> USB & Bluetooth -> Advanced -> Compatibility -> USB2


Starting with VMware Fusion 8 your Windows 7 guests can have USB3 support, but you will have to install an additional driver.


Have a look at the following KB article for the details: http://kb.vmware.com/kb/2128105

--

Wil

| Author of Vimalin. The virtual machine Backup app for VMware Fusion, VMware Workstation and Player |
| More info at vimalin.com | Twitter @wilva
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atakacs
Enthusiast
Enthusiast

Thanks for your contribution.

What I can't quite figure out is that some drives are actually working fine while others are not.

All USB3 external drives - they are all recognized as such but for some reason about 50% of them show up as read only. No real pattern I can discern except that new, unformatted drives are never seen as R/W. Bit baffling.

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wila
Immortal
Immortal

Hi,

VMware their USB implementation isn't flawless, it's pretty good, but there can be times things aren't working out.

There are certainly issues once a USB device depends on less standard features or when the device has a quirky implementation detail.

Their USB2 implementation is more solid as the USB3 variant at this time of writing as it has had a lot more exposure to all kinds of devices.

There are ways to troubleshoot, add specific vmx commands to address quirky behavior, etc...

Probably the best thing to do is that if you have a device like that is to open a ticket with VMware to try and have them reproduce the issue.

--

Wil

| Author of Vimalin. The virtual machine Backup app for VMware Fusion, VMware Workstation and Player |
| More info at vimalin.com | Twitter @wilva
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bluefirestorm
Champion
Champion

No real pattern I can discern except that new, unformatted drives are never seen as R/W.

If the Windows 7 VM belongs to a domain, there might be a domain security policy that prevents it. But this doesn't explain why it works for some but not at all for others.

The security policy is "Devices: Allowed to format and eject removable media".

I pasted a screenshot from a Windows 10, gpedit.msc

pastedImage_1.png

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ColoradoMarmot
Champion
Champion

That's particularly true for Windows 7. 

I wonder if the partition and format of the drives might have something to do with it.

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