VirtualBox

source: vbox/trunk/doc/manual/en_US/user_KnownIssues.xml@ 37872

Last change on this file since 37872 was 37727, checked in by vboxsync, 14 years ago

manual/changelog: preserve the aspect ratio in scale mode

File size: 8.7 KB
Line 
1<?xml version="1.0" encoding="UTF-8"?>
2<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
3"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
4<chapter id="KnownIssues">
5 <title>Known limitations</title>
6
7 <para>This sections describes known problems with VirtualBox
8 $VBOX_VERSION_STRING. Unless marked otherwise, these issues are planned to
9 be fixed in later releases.</para>
10
11 <itemizedlist>
12 <listitem>
13 <para>The following <emphasis role="bold">Guest SMP (multiprocessor)
14 limitations</emphasis> exist:<itemizedlist>
15 <listitem>
16 <para><emphasis role="bold">Poor performance</emphasis> with
17 32-bit guests on AMD CPUs. This affects mainly Windows and Solaris
18 guests, but possibly also some Linux kernel revisions. Partially
19 solved in 3.0.6 for 32 bits Windows NT, 2000, XP and 2003 guests.
20 Requires 3.0.6 or higher Guest Additions to be installed.</para>
21 </listitem>
22
23 <listitem>
24 <para><emphasis role="bold">Poor performance</emphasis> with
25 32-bit guests on certain Intel CPU models that do not include
26 virtual APIC hardware optimization support. This affects mainly
27 Windows and Solaris guests, but possibly also some Linux kernel
28 revisions. Partially solved in 3.0.12 for 32 bits Windows NT,
29 2000, XP and 2003 guests. Requires 3.0.12 or higher Guest
30 Additions to be installed.</para>
31 </listitem>
32 </itemizedlist></para>
33 </listitem>
34
35 <listitem>
36 <para><emphasis role="bold">64-bit guests on some 32-bit host systems
37 with VT-x</emphasis> can cause instabilities to your system. If you
38 experience this, do not attempt to execute 64-bit guests. Refer to the
39 VirtualBox user forum for additional information.</para>
40 </listitem>
41
42 <listitem>
43 <para>For <emphasis role="bold">Direct3D support in Windows
44 guests</emphasis> to work, the Guest Additions must be installed in
45 Windows "safe mode". Press F8 when the Windows guest is booting and
46 select "Safe mode", then install the Guest Additions. Otherwise Windows'
47 file protection mechanism will interfere with the replacement DLLs
48 installed by VirtualBox and keep restoring the original Windows system
49 DLLs.</para>
50 </listitem>
51
52 <listitem>
53 <para><emphasis role="bold">Guest control.</emphasis> On Windows guests,
54 a process lauched via the guest control execute support will not be able
55 to display a graphical user interface <emphasis>unless</emphasis> the
56 user account under which it is running is currently logged in and has a
57 desktop session.</para>
58
59 <para>Also, to use accounts without or with an empty password, the
60 guest's group policy must be changed. To do so, open the group policy
61 editor on the command line by typing
62 <computeroutput>gpedit.msc</computeroutput>, open the key
63 <emphasis>Computer Configuration\Windows Settings\Security
64 Settings\Local Policies\Security Options</emphasis> and change the value
65 of <emphasis>Accounts: Limit local account use of blank passwords to
66 console logon only</emphasis> to <emphasis>Disabled</emphasis>.</para>
67 </listitem>
68
69 <listitem>
70 <para><emphasis role="bold">Compacting virtual disk images is limited to
71 VDI files.</emphasis> The <code>VBoxManage modifyhd --compact</code>
72 command is currently only implemented for VDI files. At the moment the
73 only way to optimize the size of a virtual disk images in other formats
74 (VMDK, VHD) is to clone the image and then use the cloned image in the
75 VM configuration.</para>
76 </listitem>
77
78 <listitem>
79 <para><emphasis role="bold">OVF import/export:</emphasis><itemizedlist>
80 <listitem>
81 <para>OVF localization (multiple languages in one OVF file) is not
82 yet supported.</para>
83 </listitem>
84
85 <listitem>
86 <para>Some OVF sections like StartupSection,
87 DeploymentOptionSection and InstallSection are ignored.</para>
88 </listitem>
89
90 <listitem>
91 <para>OVF environment documents, including their property sections
92 and appliance configuration with ISO images, are not yet
93 supported.</para>
94 </listitem>
95
96 <listitem>
97 <para>Remote files via HTTP or other mechanisms are not yet
98 supported.</para>
99 </listitem>
100 </itemizedlist></para>
101 </listitem>
102
103 <listitem>
104 <para>Neither <emphasis role="bold">scale mode</emphasis> nor <emphasis
105 role="bold">seamless mode</emphasis> work correctly with guests using
106 OpenGL 3D features (such as with compiz-enabled window managers).</para>
107 </listitem>
108
109 <listitem>
110 <para>Preserving the aspect ratio in scale mode works only on Windows
111 hosts and on Mac OS X hosts.</para>
112 </listitem>
113
114 <listitem>
115 <para>On <emphasis role="bold">Mac OS X hosts,</emphasis> the following
116 features are not yet implemented: </para>
117
118 <para><itemizedlist>
119 <listitem>
120 <para>Numlock emulation</para>
121 </listitem>
122
123 <listitem>
124 <para>CPU frequency metric</para>
125 </listitem>
126
127 <listitem>
128 <para>Memory ballooning</para>
129 </listitem>
130 </itemizedlist></para>
131 </listitem>
132
133 <listitem>
134 <para><emphasis role="bold">Mac OS X Server guests:</emphasis>
135 <itemizedlist>
136 <listitem>
137 <para>Mac OS X Server guests can only run on a certain host
138 hardware. For details about license and host hardware limitations,
139 please see <xref linkend="intro-macosxguests" />.</para>
140 </listitem>
141
142 <listitem>
143 <para>VirtualBox does not provide Guest Additions for Mac OS X
144 Server at this time.</para>
145 </listitem>
146
147 <listitem>
148 <para>The graphics resolution currently defaults to 1024x768 as
149 Mac OS X Server falls back to the built-in EFI display support.
150 See <xref linkend="efividmode" /> for more information on how to
151 change EFI video modes.</para>
152 </listitem>
153
154 <listitem>
155 <para>Even when idle, Mac OS X Server guests currently burn 100%
156 CPU. This is a power management issue that will be addressed in a
157 future release.</para>
158 </listitem>
159
160 <listitem>
161 <para>Mac OS X Server guests only work with one CPU assigned to
162 the VM. Support for SMP will be provided in a future
163 release.</para>
164 </listitem>
165
166 <listitem>
167 <para>Depending on your system and version of Mac OS X Server, you
168 might experience guest hangs after some time. This can be fixed by
169 turning off energy saving (set timeout to "Never") in the system
170 preferences.</para>
171 </listitem>
172
173 <listitem>
174 <para>By default, the VirtualBox EFI enables debug output of the
175 Mac OS X Server kernel to help you diagnose boot problems. Note
176 that there is a lot of output and not all errors are fatal (they
177 would also show on your physical Mac). You can turn off these
178 messages by issuing this command:<screen>VBoxManage setextradata "VM name" "VBoxInternal2/EfiBootArgs" " "</screen>To
179 revert to the previous behavior, use:<screen>VBoxManage setextradata "VM name" "VBoxInternal2/EfiBootArgs" ""</screen></para>
180 </listitem>
181 </itemizedlist></para>
182 </listitem>
183
184 <listitem>
185 <para><emphasis role="bold">Solaris hosts:</emphasis> <itemizedlist>
186 <listitem>
187 <para>There is no support for USB devices connected to Solaris 10
188 hosts.</para>
189 </listitem>
190
191 <listitem>
192 <para>USB support on Solaris hosts requires kernel version snv_124
193 or higher. Webcams and other isochronous devices are known to have
194 poor performance.</para>
195 </listitem>
196
197 <listitem>
198 <para>No ACPI information (battery status, power source) is
199 reported to the guest.</para>
200 </listitem>
201
202 <listitem>
203 <para>No support for using wireless adapters with bridged
204 networking.</para>
205 </listitem>
206 </itemizedlist></para>
207 </listitem>
208
209 <listitem>
210 <para><emphasis role="bold">Guest Additions for OS/2.</emphasis> Shared
211 folders are not yet supported with OS/2 guests. In addition, seamless
212 windows and automatic guest resizing will probably never be implemented
213 due to inherent limitations of the OS/2 graphics system.</para>
214 </listitem>
215 </itemizedlist>
216</chapter>
Note: See TracBrowser for help on using the repository browser.

© 2025 Oracle Support Privacy / Do Not Sell My Info Terms of Use Trademark Policy Automated Access Etiquette