virtualbox.org

I thought I better ask this in a seperate post. I am running (now) VB 4.2.1 on OSX 10.8.2. I can't launch more than one guest at a time. I get this error...

Failed to open a session for the virtual machine (any second guest vm)
PIIX3 cannot attach drive to the Secondary Master (VERR_SHARING_VIOLATION)

first of all the only thing on any of my guests using the IDE controller is the Host CD/DVD drive and that is set to PIIX4. I used to be able to open multiple guests. all guests run just fine on their own.

The message says that you have the same disk image mounted in multiple VMs, hence the sharing violation. Same ISO mounted perhaps?

mpack wrote:The message says that you have the same disk image mounted in multiple VMs, hence the sharing violation. Same ISO mounted perhaps?

I do have a shared folder for each guest pointing to the same partition on an external drive. I tried deleting the shared folder in the second guest before launching it but I get the same error.

someone suggested perhaps my VirtualBox.xml file might be corrupted. I don't know enough about what to look for so I am attaching it here...

none of the install .iso's exist on the system anymore and they aren't listed in the media manager so I assume that's not a problem.

I see that two people have downloaded my xml file. I don't know if it was moderators, developers or end users but if someone sees anything wrong, or if they see nothing is wrong, I would like to know.

thank you

I didn't ask for your VirtualBox.xml - it isn't relevant, hence I'm not one of its viewers. In v4 and later the media registry for a VM is inside the .vbox file, and in your case you may need to check the .vbox files of the two conflicting VMs - you should find that they both mount the same disk image, resulting in the error message you quoted.

mpack wrote:I didn't ask for your VirtualBox.xml - it isn't relevant, hence I'm not one of its viewers. In v4 and later the media registry for a VM is inside the .vbox file, and in your case you may need to check the .vbox files of the two conflicting VMs - you should find that they both mount the same disk image, resulting in the error message you quoted.

well I will look in the .vbox file. thank you for the info. the problem I am having though is no VM will open with any other VM. they can't all be trying to open the same disk image or can they?

I would gather the data first, speculate later.

mpack wrote:I would gather the data first, speculate later.

Perhaps this is the problem. Every VM I have has a shared folder that points to the same partition on an external HD. I tried deleting the shared folder in one guest to see if another VM would then open. Didn't work. The only other disk all VM's would have in common is the host CD/DVD drive. I have 20+ guests and I'm not sure what exactly I am suppose to gather.

Multiple applications accessing the same folder should not be a problem, unless you (the user account running VBox) have no right of access to that folder. Multiple applications attempting to open the same file with exclusive access (or write) rights will definitely cause a problem.

mpack wrote:Multiple applications accessing the same folder should not be a problem, unless you (the user account running VBox) have no right of access to that folder. Multiple applications attempting to open the same file with exclusive access (or write) rights will definitely cause a problem.

that's what I thought. I had multiple VMs running before, all accessing the same partition through a shared folder. I have read/write access to the partition so I'm not sure what is going on. perhaps I need to set the read/write access to the entire HD the partition lives on?

edit: is it possible that the first guest that is opened takes control of the shared folder and therefore any subsequent guest can't open it or give that error?

loukingjr wrote:edit: is it possible that the first guest that is opened takes control of the shared folder and therefore any subsequent guest can't open it or give that error?

AFAIK there is no such thing as "taking control of a folder". A folder is basically just an address - a location for data. Only actual editable objects need solutions to handle sharing.

mpack wrote:

loukingjr wrote:edit: is it possible that the first guest that is opened takes control of the shared folder and therefore any subsequent guest can't open it or give that error?

AFAIK there is no such thing as "taking control of a folder". A folder is basically just an address - a location for data. Only actual editable objects need solutions to handle sharing.

well I'm at a loss then. I have permissions to access the partition in question. every VM I have can read and write to it through the shared folder. I just can't open more than one VM at a time because of the error I am getting and I have no idea why. It's actually not critical to me. I have no reason to have more than one VM open at a time but it's just puzzling.

loukingjr wrote:Failed to open a session for the virtual machine (any second guest vm)
PIIX3 cannot attach drive to the Secondary Master (VERR_SHARING_VIOLATION)

It appears to be an issue of a virtual machine setting. How about some info from the vms?

ChipMcK wrote:

loukingjr wrote:Failed to open a session for the virtual machine (any second guest vm)
PIIX3 cannot attach drive to the Secondary Master (VERR_SHARING_VIOLATION)

It appears to be an issue of a virtual machine setting. How about some info from the vms?

Chip? is there a vms file or do I have to type the settings out by hand? I have more than 20 VMs

edit: I got them. I'm attaching the .vbox files from two of the VMs