File corruption on shared folder - Linux host + Windows 7 guest

[Parazythum]

Setup : Host : Ubuntu 16.04 x64 Guest : Windows 7 x64 Shared folder (on ext4 partition) between host and guest

I'm using a Windows 7 virtual machine only for Adobe Photoshop CS6 x64.

Before v6.0.8 I installed v6.0.6 only briefly, I had to revert back to 6.0.4 because of the mouse integration bug. So I for the present issue I installed 6.0.8 over 6.0.4.

I encountered a strange behaviour with the shared folder I'm using to exchange files between the host and the guest. In Photoshop CS6 x64, after I installed VirtualBox v6.0.8, sometimes Photoshop tells me it couldn't read the TIFF files I had worked on before. And when it could, sometimes the content was scrambled. I checked my images in other software (under Windows and Ubuntu) : correct. I opened the files in the VM with Photoshop CS6 x32 this time : correct. I checked my TIFF files with an utility called jHove, which checks the TIF file integrity : no errors. So my image files are without flaws. I can save them in Photoshop but not read them back, at least in the x64 version. Weird. I also copied the files directly on the guest : this time Photoshop CS6 x64 was happy.

For 2 days I have tested many things. It only occurs in Photoshop CS6 x64, when I'm using the shared folder.

So I decided to revert back to VirtualBox v6.0.4, and dang! Photoshop CS6 x64 was happy again with my files...

So my conclusion is the problem comes from the shared folder functions, but only when reading my files, not when I'm writing.

I'm including my v6.0.4 last log file, I didn't think about saving one when I was under v6.0.8 sorry.

[bird]

Did you upgrade the guest additions?

[bird]

Wonder if you could share one of the problematic TIFF files, or give some clue as to their dimensions, file size and such. Would make it easier to reproduce the issue.

[bird]

I've not been able to reproduce the issue.

[Parazythum]

Replying to bird:

Did you upgrade the guest additions?

Yes I upgraded the guest additions, installed in safe mode

[Parazythum]

Replying to bird:

Wonder if you could share one of the problematic TIFF files, or give some clue as to their dimensions, file size and such. Would make it easier to reproduce the issue.

The TIF files are not very big : ~20Mpx (5192x3896, 8-bit RGB) - Total file size LZW-compressed = 42Mb I also checked the file permissions, set them to 777.

The problem is not the files themselves : when I'm trying to read them from the shared resource, some seem corrupt, others not. Sometimes when they are read the content is corrupt, sometimes not. When Photoshop tells me they are corrupt, it's always the same files so it's not a random problem. What makes me say that the problem comes from the shared resource : when I copy the images on the Windows 7 VM's drive (for example c:\temp), Photoshop reads them all! Also, the problem occurs only in Photoshop x64, NOT using the x32 version. xnViewMP x64 reads the files alright from the shared resource.

Looking at the versions history, I saw that there were changes made in the shared resources code in VirtualBox v6.06, maybe there was a bug introduced?

[Parazythum]

I just tried the same VM on another computer with VirtualBox v6.0.8, a folder shared the same way on an ext4 partition, the same images.

I can't reproduce the problem :(

I'll have to wait to return home in a few days to test again on the first computer... this time with v6.0.8 or even v6.0.9 so I can send you the log file

[Parazythum]

OK here is an update.

I upgraded the packages on my ubuntu 16.04, I am now in kernel version 4.4.0-150 I reinstalled VirtualBox v6.0.8. Launched, tried Photoshop: all went well, it loaded my images. But I still had Guest Additions v6.0.4 installed. So I installed the v6.0.8 Guest Additions (in safe mode of course). Rebooted. Tried Photoshop: errors on my files. Ah-ah!

Attachment : the log file, from this last attempt with v6.0.8 this time (I replaced the old one).

I also checked my downloaded Guest Additions v6.0.8 ISO: the MD5sum is correct.

I'll try to get back to Guest Additions 6.0.6, to tell you if it works with this version.

[Parazythum]

Test with VB 6.0.8 + Guest Additions 6.0.6: all good ! This time it's obvious: the errors only occur with the Guest Additions 6.0.8.

Log file attached.