Sun Microsystems VERSION 3.1.0_BETA2 User Manual
11 Troubleshooting
11.5.4 Linux host floppy not found
The previous instructions (for CD and DVD drives) apply accordingly to floppy disks,
except that on older distributions VirtualBox tests for /dev/fd* devices by default,
and this can be overridden with the VBOX_FLOPPY environment variable.
except that on older distributions VirtualBox tests for /dev/fd* devices by default,
and this can be overridden with the VBOX_FLOPPY environment variable.
11.5.5 Strange guest IDE error messages when writing to CD/DVD
If the experimental CD/DVD writer support is enabled with an incorrect VirtualBox,
host or guest configuration, it is possible that any attempt to access the CD/DVD writer
fails and simply results in guest kernel error messages (for Linux guests) or applica-
tion error messages (for Windows guests). VirtualBox performs the usual consistency
checks when a VM is powered up (in particular it aborts with an error message if the
device for the CD/DVD writer is not writable by the user starting the VM), but it can-
not detect all misconfigurations. The necessary host and guest OS configuration is not
specific for VirtualBox, but a few frequent problems are listed here which occurred in
connection with VirtualBox.
host or guest configuration, it is possible that any attempt to access the CD/DVD writer
fails and simply results in guest kernel error messages (for Linux guests) or applica-
tion error messages (for Windows guests). VirtualBox performs the usual consistency
checks when a VM is powered up (in particular it aborts with an error message if the
device for the CD/DVD writer is not writable by the user starting the VM), but it can-
not detect all misconfigurations. The necessary host and guest OS configuration is not
specific for VirtualBox, but a few frequent problems are listed here which occurred in
connection with VirtualBox.
Special care must be taken to use the correct device. The configured host CD/DVD
device file name (in most cases /dev/cdrom) must point to the device that allows
writing to the CD/DVD unit. For CD/DVD writer units connected to a SCSI controller
or to a IDE controller that interfaces to the Linux SCSI subsystem (common for some
SATA controllers), this must refer to the SCSI device node (e.g. /dev/scd0). Even
for IDE CD/DVD writer units this must refer to the appropriate SCSI CD-ROM device
node (e.g. /dev/scd0) if the ide-scsi kernel module is loaded. This module is required
for CD/DVD writer support with all Linux 2.4 kernels and some early 2.6 kernels.
Many Linux distributions load this module whenever a CD/DVD writer is detected in
the system, even if the kernel would support CD/DVD writers without the module.
VirtualBox supports the use of IDE device files (e.g. /dev/hdc), provided the kernel
supports this and the ide-scsi module is not loaded.
writing to the CD/DVD unit. For CD/DVD writer units connected to a SCSI controller
or to a IDE controller that interfaces to the Linux SCSI subsystem (common for some
SATA controllers), this must refer to the SCSI device node (e.g. /dev/scd0). Even
for IDE CD/DVD writer units this must refer to the appropriate SCSI CD-ROM device
node (e.g. /dev/scd0) if the ide-scsi kernel module is loaded. This module is required
for CD/DVD writer support with all Linux 2.4 kernels and some early 2.6 kernels.
Many Linux distributions load this module whenever a CD/DVD writer is detected in
the system, even if the kernel would support CD/DVD writers without the module.
VirtualBox supports the use of IDE device files (e.g. /dev/hdc), provided the kernel
supports this and the ide-scsi module is not loaded.
Similar rules (except that within the guest the CD/DVD writer is always an IDE
device) apply to the guest configuration. Since this setup is very common, it is likely
that the default configuration of the guest works as expected.
that the default configuration of the guest works as expected.
11.5.6 VBoxSVC IPC issues
On Linux, VirtualBox makes use of a custom version of Mozilla XPCOM (cross plat-
form component object model) for inter- and intra-process communication (IPC). The
process VBoxSVC serves as a communication hub between different VirtualBox pro-
cesses and maintains the global configuration, i.e. the XML database. When starting
a VirtualBox component, the processes VBoxSVC and VirtualBoxXPCOMIPCD are
started automatically. They are only accessible from the user account they are running
under. VBoxSVC owns the VirtualBox configuration database which normally resides
in ˜
form component object model) for inter- and intra-process communication (IPC). The
process VBoxSVC serves as a communication hub between different VirtualBox pro-
cesses and maintains the global configuration, i.e. the XML database. When starting
a VirtualBox component, the processes VBoxSVC and VirtualBoxXPCOMIPCD are
started automatically. They are only accessible from the user account they are running
under. VBoxSVC owns the VirtualBox configuration database which normally resides
in ˜
/.VirtualBox
. While it is running, the configuration files are locked. Com-
munication between the various VirtualBox components and VBoxSVC is performed
through a local domain socket residing in /tmp/.vbox-<username>-ipc. In case
through a local domain socket residing in /tmp/.vbox-<username>-ipc. In case
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