USB not working
If USB is not working on your Linux host, make sure that the current user is a member of the vboxusers group. On older hosts, you need to make sure that the user has permission to access the USB filesystem (usbfs), which VirtualBox relies on to retrieve valid information about your host's USB devices. The rest of this section only applies to those older systems.
Note
The current rdesktop-vrdp implementation does not support accessing USB devices through the sysfs!
As usbfs is a virtual filesystem, a chmod on /proc/bus/usb has no effect. The permissions for usbfs can therefore only be changed by editing the /etc/fstab file.
For example, most Linux distributions have a user group called usb or similar, of which the current user must be a member. To give all users of that group access to usbfs, make sure the following line is present:
# 85 is the USB group
none /proc/bus/usb usbfs devgid=85,devmode=664 0 0
Replace 85 with the group ID that matches your system (search /etc/group for "usb" or similar). Alternatively, if you don't mind the security hole, give all users access to USB by changing "664" to "666".
The various distributions are very creative from which script the usbfs filesystem is mounted. Sometimes the command is hidden in unexpected places. For SuSE 10.0 the mount command is part of the udev configuration file /etc/udev/rules.d/50-udev.rules. As this distribution has no user group called usb, you may e.g. use the vboxusers group which was created by the VirtualBox installer. Since group numbers are allocated dynamically, the following example uses 85 as a placeholder. Modify the line containing (a linebreak has been inserted to improve readability)
DEVPATH="/module/usbcore", ACTION=="add",
RUN+="/bin/mount -t usbfs usbfs /proc/bus/usb"
and add the necessary options (make sure that everything is in a single line):
DEVPATH="/module/usbcore", ACTION=="add",
RUN+="/bin/mount -t usbfs usbfs /proc/bus/usb -o devgid=85,devmode=664"
Debian Etch has the mount command in /etc/init.d/mountkernfs.sh. Since that distribution has no group usb, it is also the easiest solution to allow all members of the group vboxusers to access the USB subsystem. Modify the line
domount usbfs usbdevfs /proc/bus/usb -onoexec,nosuid,nodev
so that it contains
domount usbfs usbdevfs /proc/bus/usb -onoexec,nosuid,nodev,devgid=85,devmode=664
As usual, replace the 85 with the actual group number which should get access to USB devices.
Other distributions do similar operations in scripts stored in the /etc/init.d directory.
PAX/grsec kernels
Linux kernels including the grsec patch (see
http://www.grsecurity.net/) and derivates have to disable PAX_MPROTECT for the VBox binaries to be able to start a VM. The reason is that VBox has to create executable code on anonymous memory.
Linux kernel vmalloc pool exhausted
When running a large number of VMs with a lot of RAM on a Linux system (say 20 VMs with 1GB of RAM each), additional VMs might fail to start with a kernel error saying that the vmalloc pool is exhausted and should be extended. The error message also tells you to specify vmalloc=256MB in your kernel parameter list. If adding this parameter to your GRUB or LILO configuration makes the kernel fail to boot (with a weird error message such as "failed to mount the root partition"), then you have probably run into a memory conflict of your kernel and initial RAM disk. This can be solved by adding the following parameter to your GRUB configuration:
uppermem 524288
Тема: USB в VirtualBox 3.1 под 10.04 (Прочитано 28901 раз)
