Sun Microsystems 3.0.0 Linux hosts, Running an iSCSI initiator and target on a single system

11Troubleshooting

11.4.4Running an iSCSI initiator and target on a single system

Deadlocks can occur on a Windows host when attempting to access an iSCSI target running in a guest virtual machine with an iSCSI initiator (e.g. Microsoft iSCSI Ini- tiator) that is running on the host. This is caused by a flaw in the Windows cache manager component, and causes sluggish host system response for several minutes, followed by a “Delayed Write Failed” error message in the system tray or in a sepa- rate message window. The guest is blocked during that period and may show error messages or become unstable.

Setting the environment variable VBOX_DISABLE_HOST_DISK_CACHE to 1 will enable a workaround for this problem until Microsoft addresses the issue. For example, open a command prompt window and start VirtualBox like this:

set VBOX_DISABLE_HOST_DISK_CACHE=1 VirtualBox

While this will decrease guest disk performance (especially writes), it does not affect the performance of other applications running on the host.

11.5 Linux hosts

11.5.1 Linux kernel module refuses to load

If the VirtualBox kernel module (vboxdrv) refuses to load, i.e. you get an “Error in- serting vboxdrv: Invalid argument”, check (as root) the output of the dmesg command to find out why the load failed. The most common reasons are:

•With Linux 2.6.19 and higher, the NMI watchdog may be active. Add nmi_watchdog=0 to the kernel command line (e.g. in your grub configu- ration) and reboot. With the Debian and Ubuntu installation modules, execute sudo dpkg-reconfigure virtualbox again.

•The kernel disagrees about the version of the gcc used to compile the module. Make sure that you use the same compiler as used to build the kernel.

11.5.2 Linux host CD/DVD drive not found

If you have configured a virtual machine to use the host’s CD/DVD drive, but this does not appear to work, make sure that the current user has permission to access the corresponding Linux device file (/dev/hdc or /dev/scd0 or /dev/cdrom or similar). On most distributions, the user must be added to a corresponding group (usually called cdrom or cdrw).

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