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USB device : how to prevent capture ?

PostPosted: 11. Jan 2019, 16:56
by JoTaPe
context : guest VBox Snow Leopard, host is High sierra 10.13.6
When the VM starts it captures all my USB devices, especially scanner, printer and external USB disks, which are no more available in the HSierra host.
How can I avoid this ?

Re: USB device : how to prevent capture ?

PostPosted: 11. Jan 2019, 21:16
by socratis
Remove the blank USB filter that you most probably have in your VM Settings > Ports > USB. And then do yourself a favor and read the "USB basics and troubleshooting", all of the posts. It will come in handy...

Re: USB device : how to prevent capture ?

PostPosted: 12. Jan 2019, 06:39
by JoTaPe
OK, I RTFM but didn't found anything understandable for me.
Hope I will be more lucky in the forum :-)

JP

Re: USB device : how to prevent capture ?

PostPosted: 12. Jan 2019, 07:22
by JoTaPe
I have read and built a filter for my USB scanner, inactivated.
Is it right to understand that a blank filter implies the capture of all the USB devices connected to the host and, if at least one filter exists (ex: my Canoscan), no device will be automatically captured but the mouse and the keyboard and the filtered device if its filter is activated ?

Re: USB device : how to prevent capture ?

PostPosted: 12. Jan 2019, 09:58
by socratis
JoTaPe wrote:I RTFM but didn't found anything understandable for me.
JoTaPe wrote:Is it right to understand that a blank filter implies the capture of all the USB devices connected to the host

From TFM that you read, there's the following in #4: USB Filters:
#4: USB Filters
A USB filter is a series of "AND" conditional statements. So when you're filling in the filter values, you're telling the filter:
Capture a device with this VendorID, AND that ProductID, AND ...
A blank filter (not recommended!) will match anything, which is good if the device appears as a composite, i.e. presents as a number of different devices all connected at once. However the danger of a blank filter is the potential to grab the wrong device, e.g. you do not want to grab the host's USB keyboard and assign it to the guest! If you have a problem with the wrong device being grabbed then you'll need to add just enough information to the filter so that it matches your device only. But don't define the filter too narrowly, as that can lead to problems too. That's why your safest bet for a basic filter is to fill in the VendorID and ProductID only.

So, please, do both of us a favor and re-read the thread, twice.

And if you still can't figure out what's going on, right-click on the VM in the VirtualBox Manager, select "Show in Finder". ZIP the selected ".vbox" file and attach it in your response.

Re: USB device : how to prevent capture ?

PostPosted: 12. Jan 2019, 19:39
by JoTaPe
Hi,
I have read parts of T official FM, but your answer here in the forum looks a better one to my problem.
This official manual is not for simple users at all.
What about the second part of my assertion ?
if at least one filter exists (ex: my Canoscan), no device will be automatically captured but the mouse and the keyboard and the filtered device if its filter is activated ?

Thanks for your kind attention.

JP the only one user of VBox on a Mac in Chile ? :-)

Re: USB device : how to prevent capture ?

PostPosted: 12. Jan 2019, 20:09
by socratis
JoTaPe wrote:I have read parts of T official FM, but your answer here in the forum looks a better one to my problem.
That's really interesting, because *I* am the one that wrote the FAQ, and I simply quoted the FAQ, I didn't add or subtract anything, I just highlighted some things... :roll:

JoTaPe wrote:What about the second part of my assertion ?
I do not like repeating myself, that's why I spent *a lot* of time writing the FAQ. The least you could do is spend 1/2 hour to read it properly, all the answers are there, in the #4: USB Filters section. But, please read the whole thread...