Sun Microsystems VIRTUALBOX VERSION 3.1.0_BETA2 - Manual (Page 159)

11 Troubleshooting
11.3 Linux and X11 guests
11.3.1 Linux guests may cause a high CPU load
Some Linux guests may cause a high CPU load even if the guest system appears to
be idle. This can be caused by a high timer frequency of the guest kernel. Some
Linux distributions, for example Fedora, ship a Linux kernel configured for a timer
frequency of 1000Hz. We recommend to recompile the guest kernel and to select a
timer frequency of 100Hz.
11.3.2 AMD Barcelona CPUs
Most Linux-based guests will fail with AMD Phenoms or Barcelona-level Opterons due
to a bug in the Linux kernel. Enable the I/O-APIC to work around the problem (see
chapter
3.3.2 , “Advanced” tab , page 46 ).
11.3.3 Buggy Linux 2.6 kernel versions
The following bugs in Linux kernels prevent them from executing correctly in
VirtualBox, causing VM boot crashes:
• The Linux kernel version 2.6.18 (and some 2.6.17 versions) introduced a race
condition that can cause boot crashes in VirtualBox. Please use a kernel version
2.6.19 or later.
• With hardware virtualization and the I/O APIC enabled, kernels before 2.6.24-
rc6 may panic on boot with the following message:
Kernel panic - not syncing: IO-APIC + timer doesn’t work! Boot with
apic=debug and send a report. Then try booting with the ’noapic’ option
If you see this message, either disable hardware virtualization or the I/O APIC
(see chapter
3.4 , System settings , page 47 ), or upgrade the guest to a newer
kernel. 2
11.3.4 Shared clipboard, auto-resizing and seamless desktop in
X11 guests
Guest desktop services in guests running the X11 window system (Solaris, Linux and
others) are provided by a guest service called VBoxClient, which runs under the
ID of the user who started the desktop session and is automatically started using the
following command lines
2 See http://www.mail-archive.com/[email protected]/msg30813.
html for details about the kernel fix.
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