Windows 10 guest crashes AND destroys MBR-host permissions

[old-man]

While my search capabilities are not the greatest, I could not find anything relating to MBR corruption.

I'm attempting to run Win 10 in VB Linux Mint 17.3 host which is a dual-boot system with W10. I've been attempting this on several versions of VB with similar results.

Here's the problem: The W10 guest crashes/freezes and somehow does damage to the host file system including the MBR. After the freeze I close the VM/VB and attempt to reboot Linux. Since I almost always have Firefox running, it fails to shutdown properly and I get a notice of improper file permissions as it attempts to record the session. Also, if I attempt file actions (reading, writing, etc.) the same permission notices pop up. Unfortunately, I have no screen shots of those popups. But, the major kicker is that my machine then fails to reboot telling me no OS present. Running my live USB of Boot-Repair fails also and simply keeps scanning. The solution is a bit lengthy for this old man but it requires me rebuilding the MBR using Windows rescue disc and then running Boot-Repair to get back to square one. Upon reboot Linux then instructs to Press F for scanning and repairing. Appropriate logs/text are attached.

System-info.txt

(2.04 KiB) Downloaded 10 times

vbox-install.log.zip

(34.56 KiB) Downloaded 5 times

vboxmanage showvminfo W10-64-2.txt

(3.12 KiB) Downloaded 8 times

Edited to remove duplicate attachment.

[old-man]

VM log:

W10-64-2-2017-05-07-16-03-16.log.zip

(16.7 KiB) Downloaded 10 times

[socratis]

I'm attempting to run Win 10 in VB Linux Mint 17.3 host which is a dual-boot system with W10.

Are you using rawdisk access to access the Win10 partition from within Linux? Do I understand this correctly?

[old-man]

I'm attempting to run Win 10 in VB Linux Mint 17.3 host which is a dual-boot system with W10.

Are you using rawdisk access to access the Win10 partition from within Linux? Do I understand this correctly?

Darn, I don't know what that means....

[old-man]

If you're talking about Linux accessing the virtual machine (Win10 guest), no. However, as a Linux/Win10 dual boot machine I do from time to time access one of the Win10 partitions from within Linux and Win10 VM. But, I never access the Win10 VM VDI.

[mpack]

If two PCs access the same hard disk, and both think they're in charge, corruption is virtually guaranteed. If you have a Linux host and a Windows 10 VM both accessing an NTFS partition used by the Win10 half of the dual boot - then quite obviously you can expect catastrophic results. There is a good reason why the user manual contains the following warning regarding raw disk access.

Warning

Raw hard disk access is for expert users only. Incorrect use or use of an outdated configuration can lead to total loss of data on the physical disk. Most importantly, do not attempt to boot the partition with the currently running host operating system in a guest. This will lead to severe data corruption.

Personally I'd say - go for it. The painful memories will probably be a far better teacher than any warnings I (or the user manual) can give.

[old-man]

Hmmmm....then why does VB have a setting for Shared Folders if it's not advisable?

[socratis]

Can you please try once again the description of your setup? This time while clearly identifying which is the host, which is the guest, which one accesses what, what's breaking down, in the exact scenario. I, personally, got a little bit confused with the 2nd partition of Win10 and the Win10 VM. If there is no other reason, label the two bootable ones Linux and W10, and then simply use VM for the guest (I really don't care what the guest is running at this point).

[old-man]

That's a good idea --- let me gather some info and I'll try again.....

[old-man]

1. I have a dual-boot laptop; Win10/Linux Mint 17.3. The laptop was purchased with Win10 as the OS and I decided to try Linux again since it has become more friendly to us point/click folks.

2. The Win10 half of the dual-boot has two relevant partitions: one for the OS and one for data which is named "working". When I installed Linux I partioned off a portion of "working" to be the Linux partitions. Been running that for about a year or so with minimal problems. Linux has been the primary during that time.

3. I would prefer to get rid of the Win10 dual-boot portion and have Linux as the only OS. Unfortunately, there are some things that I can't get done easily in Linux --- most notably accessing and configuring my security cameras and creating DVDs. I'm no longer considered a technoid/guru and spent months trying various Linux methods for the DVDs and cameras including Zoneminder, some 3rd party stuff & Wine approach. Someone suggested I take a look at VirtualBox and a Win10 virtual machine which would allow the appropriate plug-ins for the cameras and I could stay with my go-to DVD app, ConvertXtoDVD, and not have to periodically reboot the machine into and out of Windows.

4. I setup VB, installed Win10 with Guest Additions and a Shared Folder --- the "working" partition (NTFS) which I mount in Linux as "working". I did this because the "working" partition has data and apps that the Win10 VM needs access to periodically for installation, etc.

5. At this point I'm happy as a bug-in-a-rug with not having to reboot all the time to manage cameras and create DVDs. Unfortunately the VM periodically would freeze with an error popup & would effect the entire Linux system sometimes even destroying the machine's ability to boot up --- this required rebuilding the MBR as explained at the beginning. When I would try to screen capture the popup Linux would not save it due to permissions being screwed up --- Linux wouldn't even load a USB in an attempt to write the screen capture to it.

Here's a screen of GParted:

GParted.jpg (95.53 KiB) Viewed 3257 times

sda3 is the Win10 OS partition of the dual-boot (this is never accessed from Linux or VM)
sda5 is the data partition (working)
sda6 is the Linux OS and data.

Right now, I'm running Win10 VM with the Shared Folder removed from the settings --- wanna see if the thing continues to freeze.

BTW, running the latest version of VB and Win10 in VM.

[socratis]

For future reference, "current version", "latest version", "previous version" don't (generally speaking) provide accurate information. In a couple of months the "current" will definitely be different. It's better if you use the complete version numbers (including the build numbers) to identify software.

Now, let me see if I can summarize what I've understood your setup to be:

• Setup: Host Ubuntu Mint 17.3, running VirtualBox 5.1.22, with guest Win10 ###. In the VM settings you've added a shared folder (which I assume is automount, read-write) "/media/dans/working", which is not your 2nd boot partition.
  
  Problem: The VM sometimes gets stuck (anything particular that triggers this?) and that corrupts your MBR.

Is that correct?

[old-man]

Duly noted & YES! You pretty much nailed it but I should add that I do not have the Host (Linux) share "/media/dans/working".

[socratis]

I do not have the Host (Linux) share "/media/dans/working"

Then how are you accessing your working data? You mentioned shared folders, you mentioned the "working" partition, so?

[old-man]

Like so:

shared-folders.jpg (53.13 KiB) Viewed 3244 times

Except I had it as machine folder.

[socratis]

In the VM settings you've added a shared folder (which I assume is automount, read-write) "/media/dans/working", which is not your 2nd boot partition.

I do not have the Host (Linux) share "/media/dans/working".

Like so:

Your last statement (with the picture) contradicts the previous one, while my original assumption about the share setup is 95% right. The only part that I had wrong was that 1) it's not a permanent share, it's a temporary one and 2) it's not automounted.

So, with that setup that you have, there is no way that VirtualBox is doing anything to your MBR. It can't. It doesn't have access to it. Given the whole problem, I'm thinking that it's your host that's messing with the MBR, although for the life of me I can't figure out why would it go there as well. There's absolutely no need for it.

That tidbit from the original post was interesting. This is after your VM freezes:

Since I almost always have Firefox running, it fails to shutdown properly and I get a notice of improper file permissions as it attempts to record the session. Also, if I attempt file actions (reading, writing, etc.) the same permission notices pop up.

The contents of your VM are a single file in your host. There is no way that a single file in the host is causing file permission errors on other files and corruption.

I would check the hard disk on the host for errors. Thoroughly.