virtualbox.org

I'm trying to create a virtualbox guest on an external EXFAT drive that can be moved between its original Ubuntu linux host and an OSX Mavericks host. I am experienced Ubuntu user but beginner with OSX Mavericks.

Host #1 - Ubuntu 12.04 (64-bit) running Virtualbox 4.3.6
Host #2 - OSX Mavericks running Virtualbox 4.3.6
Guest - Ubuntu 12.04 (64-bit)
.vbox/.vdi file storage - removable SSD formatted EXFAT on OSX, then mounted as EXFAT on Ubuntu using FUSE filesystem.

Both Host OS were fully updated before commencing.

Guest was created on Host #1 and runs perfectly.

On Host #1, Guest was cleanly closed, Virtualbox cleanly exited, and SSD cleanly unmounted from Host #1.

Next, SSD was transported to Host #2 (OSX Mavericks) and attached to that machine.

My goals are (1) run the guest on Host #2, and (2) copy the guest files (.vbox and .vdi)
from the SSD to the OSX machine's internal hard drive.

Problems (both attempted separately, each after a fresh startup of OSX.)

1. When trying to copy the .vdi file (without Virtualbox running) from the SSD to the OSX Mavericks hard drive, OSX copy progress indicator never leaves "zero bytes" copied indication, and after a few minutes fails with the message " ". During this time, the SSD shows continuous activity from OSX.

2. I start Virtualbox on the OSX machine, and attempt to make it accessible with Machine->Add. This step works (that is, the guest appears in the list of guests in the Virtualbox main window), however, when I try to start the guest, I see the initial guest window but it remains black screen; there is no progress after several minutes. During this time, the SSD shows continuous activity from OSX. I am unable to cleanly exit either the starting guest or the Virtualbox main window.

I speculate that something is preventing OSX from directly (or via Virtualbox) reading the .vdi file, however, I do not know how to proceed. I chose EXFAT for the SSD because it is read/write accessible from both OSX (natively) and Ubuntu (via FUSE driver), and seemed like a reasonable choice given that the underlying OS in the guest already would have journal file system, etc.

Thanks for any follow-up questions, assistance or suggestions.

Does OS X support exFAT? It's a proprietary filesystem so I find it surprising that Apple would endorse Microsoft's attempt to bite off a chunk of the portable storage market.

I have no experience of exFAT, since I'm not willing to license it just to satisfy my curiosity. However if it was to look to a host sufficiently like FAT then you could get some pretty confusing situations, like it almost working.

Sorry - posted before including the specific OSX error message dialog box that appears when copy of .vdi file is attempted:

The operation can't be completed because the item "guestname.vdi" is in use.

Several other small files and folders on the same SSD can be copied to the OSX machine without difficulty; the copy failure is only happening with the .vdi file.

What size (in bytes) is the vdi file?

1. OSX support for EXFAT was added in version 10.6.5 or thereabouts; this version (10.9.1) appears to support EXFAT. I saw some online postings discussing EXFAT problems experienced by people upgrading to OSX Mavericks (10.9) but other postings indicating that a software update had addressed the issues.

2. The VDI file is about 62 gigabytes (sized to just fill a 64 GB SSD.)

And are you sure the problem isn't simply that the copy is going very slowly? 63GB is a lot of data to copy.

In any case: VirtualBox doesn't know or care what filesystem the host uses, or what drive id or technology is used. It's the same host file I/O APIs being called each time. And certainly, file copying in the host has nothing to do with VirtualBox. If the host can't read the file then VirtualBox can't either.

I thought copying might be slow (the SSD is somewhat older and not very fast), but the copy ends with the error dialog (above) and at that point, the file shown on the OSX desktop (copy destination) has an X in the icon and zero byte length.

Let me chime in a couple of thoughts, although this does not seem to be a VBox problem as mpack said.
- ExFAT is supported in read-write mode natively.
- Check ActivityMonitor for any disk activity and %CPU. Especially if Spotlight is trying to index the SSD (mdworker).
- Try copying the .vdi from the command line.
- Try copying the .vdi from the network (if possible).
- As mpack said, 63 GB is *a lot* of data and there are a lot of things that could be "misaligned" for the whole thing to work.

As far as I can tell, spotlight is not the issue. I created the zero-length file .metadata_never_index in the root directory of the USB device, and also added the volume's name to the spotlight "privacy" list. Either/both are intended to prevent spotlight from trying to index the device.

As I believe spotlight is not the issue, and with the problem unsolved, I found that the basic problem is that VirtualBox spends several minutes trying to open the .vdi file (during which the removable device indicator LED shows activity), and then gives up. There are some error messages I collected after the several minute delay:

Could not open the medium (followed by my .vdi file name)
VDI: Error reading the block table in (my .vdi file name)
VD: error VERR_RESOURCE_BUSY opening the image file
NS_ERROR_FAILURE (0x80004005)

I searched for details about 0x80004005 but didn't find anything obviously applicable.

I used the virtual media manager to re-check the .vdi file; it takes several minutes (during which I see activity on the removable device), and fails without an error message, but the red (!) indicator remains associated with the .vdi file; which is otherwise present and on the correct path.

I am still able to run the exact same guest as long as the .vdi file is on the system hard drive (copied .vdi and .vbox to the system hard drive and ran there), but my application requires that the .vdi file be on a removable device, which is where I'm stuck.

My understanding: Have you tried the opposite, creating a vm on OS X and then starting it on Linux?

wb0gaz wrote:When trying to copy the .vdi file (without Virtualbox running) from the SSD to the OSX Mavericks hard drive, OSX copy progress indicator never leaves "zero bytes" copied indication, and after a few minutes fails with the message " ". During this time, the SSD shows continuous activity from OSX.

First of all you have to solve this. If the OS cannot operate on the file (we're talking a read-only action, copying it to the HD), then I wouldn't go a step further and try to resolve why an application cannot open the file (read-write). You have to solve the problem at a more basic level...

Thank you everyone for your patience and ideas, this problem turns out to be hardware (!) --- The SATA/USB bridge device in my external drive has some problem with OSX Mavericks.

I tested with a temporary alternate device, and everything worked as expected. I have now ordered a replacement device

socratis - thank you for your final post, you are correct, it was a more basic problem than VirtualBox (although it was good chance to learn about Spotlight and EXFAT in this time.)