| 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 | <sect1 id="ExperimentalFeatures">
|
|---|
| 7 | <title>Experimental Features</title>
|
|---|
| 8 | <para>Some VirtualBox features are labeled as experimental. Such
|
|---|
| 9 | features are provided on an "as-is" basis and are not formally
|
|---|
| 10 | supported. However, feedback and suggestions about such features are
|
|---|
| 11 | welcome. A comprehensive list of experimental features follows:</para>
|
|---|
| 12 | <itemizedlist>
|
|---|
| 13 | <listitem>
|
|---|
| 14 | <para>WDDM Direct3D video driver for Windows guests</para>
|
|---|
| 15 | </listitem>
|
|---|
| 16 | <listitem>
|
|---|
| 17 | <para>Hardware 3D acceleration support for Windows, Linux, and Solaris
|
|---|
| 18 | guests</para>
|
|---|
| 19 | </listitem>
|
|---|
| 20 | <listitem>
|
|---|
| 21 | <para>Hardware 2D video playback acceleration support for Windows
|
|---|
| 22 | guests</para>
|
|---|
| 23 | </listitem>
|
|---|
| 24 | <listitem>
|
|---|
| 25 | <para>PCI pass-through (Linux hosts only)</para>
|
|---|
| 26 | </listitem>
|
|---|
| 27 | <listitem>
|
|---|
| 28 | <para>Mac OS X guests (Mac hosts only)</para>
|
|---|
| 29 | </listitem>
|
|---|
| 30 | <listitem>
|
|---|
| 31 | <para>ICH9 chipset emulation</para>
|
|---|
| 32 | </listitem>
|
|---|
| 33 | <listitem>
|
|---|
| 34 | <para>EFI firmware</para>
|
|---|
| 35 | </listitem>
|
|---|
| 36 | <listitem>
|
|---|
| 37 | <para>Host CD/DVD drive pass-through</para>
|
|---|
| 38 | </listitem>
|
|---|
| 39 | <listitem>
|
|---|
| 40 | <para>Support of iSCSI via internal networking</para>
|
|---|
| 41 | </listitem>
|
|---|
| 42 | <listitem>
|
|---|
| 43 | <para>Synthetic CPU reporting</para>
|
|---|
| 44 | </listitem>
|
|---|
| 45 | </itemizedlist>
|
|---|
| 46 | </sect1>
|
|---|
| 47 | <sect1 id="KnownProblems">
|
|---|
| 48 | <title>Known Issues</title>
|
|---|
| 49 | <para>The following section describes known problems with VirtualBox
|
|---|
| 50 | @VBOX_VERSION_STRING@. Unless marked otherwise, these issues are planned to
|
|---|
| 51 | be fixed in later releases.</para>
|
|---|
| 52 |
|
|---|
| 53 | <itemizedlist>
|
|---|
| 54 | <listitem>
|
|---|
| 55 | <para>The following <emphasis role="bold">Guest SMP (multiprocessor)
|
|---|
| 56 | limitations</emphasis> exist:<itemizedlist>
|
|---|
| 57 | <listitem>
|
|---|
| 58 | <para><emphasis role="bold">Poor performance</emphasis> with
|
|---|
| 59 | 32-bit guests on AMD CPUs. This affects mainly Windows and Solaris
|
|---|
| 60 | guests, but possibly also some Linux kernel revisions. Partially
|
|---|
| 61 | solved in 3.0.6 for 32 bits Windows NT, 2000, XP and 2003 guests.
|
|---|
| 62 | Requires 3.0.6 or higher Guest Additions to be installed.</para>
|
|---|
| 63 | </listitem>
|
|---|
| 64 |
|
|---|
| 65 | <listitem>
|
|---|
| 66 | <para><emphasis role="bold">Poor performance</emphasis> with
|
|---|
| 67 | 32-bit guests on certain Intel CPU models that do not include
|
|---|
| 68 | virtual APIC hardware optimization support. This affects mainly
|
|---|
| 69 | Windows and Solaris guests, but possibly also some Linux kernel
|
|---|
| 70 | revisions. Partially solved in 3.0.12 for 32 bits Windows NT,
|
|---|
| 71 | 2000, XP and 2003 guests. Requires 3.0.12 or higher Guest
|
|---|
| 72 | Additions to be installed.</para>
|
|---|
| 73 | </listitem>
|
|---|
| 74 | </itemizedlist></para>
|
|---|
| 75 | </listitem>
|
|---|
| 76 |
|
|---|
| 77 | <listitem>
|
|---|
| 78 | <para><emphasis role="bold">NX (no execute, data execution
|
|---|
| 79 | prevention)</emphasis> only works for guests running on 64-bit hosts
|
|---|
| 80 | or guests running on 32-bit hosts with PAE enabled and requires that
|
|---|
| 81 | hardware virtualization be enabled.</para>
|
|---|
| 82 | </listitem>
|
|---|
| 83 |
|
|---|
| 84 | <listitem>
|
|---|
| 85 | <para>For <emphasis role="bold">basic Direct3D support in Windows
|
|---|
| 86 | guests</emphasis> to work, the Guest Additions must be installed in
|
|---|
| 87 | Windows "safe mode". Press F8 when the Windows guest is booting and
|
|---|
| 88 | select "Safe mode", then install the Guest Additions. Otherwise Windows'
|
|---|
| 89 | file protection mechanism will interfere with the replacement DLLs
|
|---|
| 90 | installed by VirtualBox and keep restoring the original Windows system
|
|---|
| 91 | DLLs. <note>
|
|---|
| 92 | <para>This does <emphasis role="bold">not</emphasis> apply to the
|
|---|
| 93 | experimental WDDM Direct3D video
|
|---|
| 94 | driver available for Vista and Windows 7 guests shipped with
|
|---|
| 95 | VirtualBox 4.1.</para>
|
|---|
| 96 | </note></para>
|
|---|
| 97 | </listitem>
|
|---|
| 98 |
|
|---|
| 99 | <listitem>
|
|---|
| 100 | <para><emphasis role="bold">Guest control.</emphasis> On Windows guests,
|
|---|
| 101 | a process lauched via the guest control execute support will not be able
|
|---|
| 102 | to display a graphical user interface <emphasis>unless</emphasis> the
|
|---|
| 103 | user account under which it is running is currently logged in and has a
|
|---|
| 104 | desktop session.</para>
|
|---|
| 105 |
|
|---|
| 106 | <para>Also, to use accounts without or with an empty password, the
|
|---|
| 107 | guest's group policy must be changed. To do so, open the group policy
|
|---|
| 108 | editor on the command line by typing
|
|---|
| 109 | <computeroutput>gpedit.msc</computeroutput>, open the key
|
|---|
| 110 | <emphasis>Computer Configuration\Windows Settings\Security
|
|---|
| 111 | Settings\Local Policies\Security Options</emphasis> and change the value
|
|---|
| 112 | of <emphasis>Accounts: Limit local account use of blank passwords to
|
|---|
| 113 | console logon only</emphasis> to <emphasis>Disabled</emphasis>.</para>
|
|---|
| 114 | </listitem>
|
|---|
| 115 |
|
|---|
| 116 | <listitem>
|
|---|
| 117 | <para><emphasis role="bold">Compacting virtual disk images is limited to
|
|---|
| 118 | VDI files.</emphasis> The <code>VBoxManage modifyhd --compact</code>
|
|---|
| 119 | command is currently only implemented for VDI files. At the moment the
|
|---|
| 120 | only way to optimize the size of a virtual disk images in other formats
|
|---|
| 121 | (VMDK, VHD) is to clone the image and then use the cloned image in the
|
|---|
| 122 | VM configuration.</para>
|
|---|
| 123 | </listitem>
|
|---|
| 124 |
|
|---|
| 125 | <listitem>
|
|---|
| 126 | <para><emphasis role="bold">OVF import/export:</emphasis><itemizedlist>
|
|---|
| 127 | <listitem>
|
|---|
| 128 | <para>OVF localization (multiple languages in one OVF file) is not
|
|---|
| 129 | yet supported.</para>
|
|---|
| 130 | </listitem>
|
|---|
| 131 |
|
|---|
| 132 | <listitem>
|
|---|
| 133 | <para>Some OVF sections like StartupSection,
|
|---|
| 134 | DeploymentOptionSection and InstallSection are ignored.</para>
|
|---|
| 135 | </listitem>
|
|---|
| 136 |
|
|---|
| 137 | <listitem>
|
|---|
| 138 | <para>OVF environment documents, including their property sections
|
|---|
| 139 | and appliance configuration with ISO images, are not yet
|
|---|
| 140 | supported.</para>
|
|---|
| 141 | </listitem>
|
|---|
| 142 |
|
|---|
| 143 | <listitem>
|
|---|
| 144 | <para>Remote files via HTTP or other mechanisms are not yet
|
|---|
| 145 | supported.</para>
|
|---|
| 146 | </listitem>
|
|---|
| 147 | </itemizedlist></para>
|
|---|
| 148 | </listitem>
|
|---|
| 149 |
|
|---|
| 150 | <listitem>
|
|---|
| 151 | <para>Neither <emphasis role="bold">scale mode</emphasis> nor <emphasis
|
|---|
| 152 | role="bold">seamless mode</emphasis> work correctly with guests using
|
|---|
| 153 | OpenGL 3D features (such as with compiz-enabled window managers).</para>
|
|---|
| 154 | </listitem>
|
|---|
| 155 |
|
|---|
| 156 | <listitem>
|
|---|
| 157 | <para>The RDP server in the VirtualBox extension pack supports only
|
|---|
| 158 | audio streams in format 22.05kHz stereo 16 bit. If the RDP client
|
|---|
| 159 | requests any other audio format there will be no audio.</para>
|
|---|
| 160 | </listitem>
|
|---|
| 161 |
|
|---|
| 162 | <listitem>
|
|---|
| 163 | <para>Preserving the aspect ratio in scale mode works only on Windows
|
|---|
| 164 | hosts and on Mac OS X hosts.</para>
|
|---|
| 165 | </listitem>
|
|---|
| 166 |
|
|---|
| 167 | <listitem>
|
|---|
| 168 | <para>On <emphasis role="bold">Mac OS X hosts,</emphasis> the following
|
|---|
| 169 | features are not yet implemented:</para>
|
|---|
| 170 |
|
|---|
| 171 | <para><itemizedlist>
|
|---|
| 172 | <listitem>
|
|---|
| 173 | <para>Numlock emulation</para>
|
|---|
| 174 | </listitem>
|
|---|
| 175 |
|
|---|
| 176 | <listitem>
|
|---|
| 177 | <para>CPU frequency metric</para>
|
|---|
| 178 | </listitem>
|
|---|
| 179 |
|
|---|
| 180 | <listitem>
|
|---|
| 181 | <para>Memory ballooning</para>
|
|---|
| 182 | </listitem>
|
|---|
| 183 | </itemizedlist></para>
|
|---|
| 184 | </listitem>
|
|---|
| 185 |
|
|---|
| 186 | <listitem>
|
|---|
| 187 | <para><emphasis role="bold">Mac OS X guests:</emphasis>
|
|---|
| 188 | <itemizedlist>
|
|---|
| 189 | <listitem>
|
|---|
| 190 | <para>Mac OS X guests can only run on a certain host hardware.
|
|---|
| 191 | For details about license and host hardware limitations, please
|
|---|
| 192 | see <xref linkend="intro-macosxguests" /> and check the Apple
|
|---|
| 193 | software license conditions.</para>
|
|---|
| 194 | </listitem>
|
|---|
| 195 |
|
|---|
| 196 | <listitem>
|
|---|
| 197 | <para>VirtualBox does not provide Guest Additions for Mac OS X
|
|---|
| 198 | at this time.</para>
|
|---|
| 199 | </listitem>
|
|---|
| 200 |
|
|---|
| 201 | <listitem>
|
|---|
| 202 | <para>The graphics resolution currently defaults to 1024x768 as
|
|---|
| 203 | Mac OS X falls back to the built-in EFI display support. See
|
|---|
| 204 | <xref linkend="efividmode" /> for more information on how to
|
|---|
| 205 | change EFI video modes.</para>
|
|---|
| 206 | </listitem>
|
|---|
| 207 |
|
|---|
| 208 | <listitem>
|
|---|
| 209 | <para>Mac OS X guests only work with one CPU assigned to the
|
|---|
| 210 | VM. Support for SMP will be provided in a future release.</para>
|
|---|
| 211 | </listitem>
|
|---|
| 212 |
|
|---|
| 213 | <listitem>
|
|---|
| 214 | <para>Depending on your system and version of Mac OS X, you
|
|---|
| 215 | might experience guest hangs after some time. This can be fixed
|
|---|
| 216 | by turning off energy saving (set timeout to "Never") in the
|
|---|
| 217 | system preferences.</para>
|
|---|
| 218 | </listitem>
|
|---|
| 219 |
|
|---|
| 220 | <listitem>
|
|---|
| 221 | <para>By default, the VirtualBox EFI enables debug output of the
|
|---|
| 222 | Mac OS X kernel to help you diagnose boot problems. Note that
|
|---|
| 223 | there is a lot of output and not all errors are fatal (they
|
|---|
| 224 | would also show on your physical Mac). You can turn off these
|
|---|
| 225 | messages by issuing this command:<screen>VBoxManage setextradata "VM name" "VBoxInternal2/EfiBootArgs" " "</screen>To
|
|---|
| 226 | revert to the previous behavior, use:<screen>VBoxManage setextradata "VM name" "VBoxInternal2/EfiBootArgs" ""</screen></para>
|
|---|
| 227 | </listitem>
|
|---|
| 228 |
|
|---|
| 229 | <listitem>
|
|---|
| 230 | <para>It is currently not possible to start a Mac OS X guest in safe mode by specifying "-x" option
|
|---|
| 231 | in "VBoxInternal2/EfiBootArgs" extradata.</para>
|
|---|
| 232 | </listitem>
|
|---|
| 233 | </itemizedlist></para>
|
|---|
| 234 | </listitem>
|
|---|
| 235 |
|
|---|
| 236 | <listitem>
|
|---|
| 237 | <para><emphasis role="bold">Solaris hosts:</emphasis> <itemizedlist>
|
|---|
| 238 | <listitem>
|
|---|
| 239 | <para>There is no support for USB devices connected to Solaris 10
|
|---|
| 240 | hosts.</para>
|
|---|
| 241 | </listitem>
|
|---|
| 242 |
|
|---|
| 243 | <listitem>
|
|---|
| 244 | <para>USB support on Solaris hosts requires Solaris 11 version
|
|---|
| 245 | snv_124 or higher. Webcams and other isochronous devices are known
|
|---|
| 246 | to have poor performance.</para>
|
|---|
| 247 | </listitem>
|
|---|
| 248 |
|
|---|
| 249 | <listitem>
|
|---|
| 250 | <para>Host Webcam passthrough is restricted to 640x480 frames at
|
|---|
| 251 | 20 frames per second due to limitations in the Solaris V4L2 API.
|
|---|
| 252 | This may be addressed in a future Solaris release.</para>
|
|---|
| 253 | </listitem>
|
|---|
| 254 |
|
|---|
| 255 | <listitem>
|
|---|
| 256 | <para>No ACPI information (battery status, power source) is
|
|---|
| 257 | reported to the guest.</para>
|
|---|
| 258 | </listitem>
|
|---|
| 259 |
|
|---|
| 260 | <listitem>
|
|---|
| 261 | <para>No support for using wireless adapters with bridged
|
|---|
| 262 | networking.</para>
|
|---|
| 263 | </listitem>
|
|---|
| 264 |
|
|---|
| 265 | <listitem>
|
|---|
| 266 | <para>Crossbow-based bridged networking on Solaris 11 hosts does
|
|---|
| 267 | not work directly with aggregate links. However, you can manually
|
|---|
| 268 | create a VNIC (using <computeroutput>dladm</computeroutput>) over
|
|---|
| 269 | the aggregate link and use that with a VM. This limitation does
|
|---|
| 270 | not exist in Solaris 11u1 build 17 and newer.</para>
|
|---|
| 271 | </listitem>
|
|---|
| 272 | </itemizedlist></para>
|
|---|
| 273 | </listitem>
|
|---|
| 274 |
|
|---|
| 275 | <listitem>
|
|---|
| 276 | <para><emphasis role="bold">Guest Additions of version 4.1, 4.1.2 and 4.1.4 for Windows</emphasis>
|
|---|
| 277 | Thus VirtualBox WDDM Video driver may be installed and kept in guest system
|
|---|
| 278 | if Guest additions uninstallation is performed.
|
|---|
| 279 | This is caused by a bug in Guest Additions uninstaller.
|
|---|
| 280 | <note>
|
|---|
| 281 | <para>This does <emphasis role="bold">not</emphasis> apply to Guest Additions update,
|
|---|
| 282 | i.e. installing a one version of Guest Additions on top of another works correctly.</para>
|
|---|
| 283 | </note>
|
|---|
| 284 | To solve this problem, one should uninstall the VirtualBox WDDM Video driver manually.
|
|---|
| 285 | To do that open Device Manager, and check whether the Display Adapter is named
|
|---|
| 286 | "VirtualBox Graphics Adapter ..". If no - there is nothing to be done. If yes - right-click
|
|---|
| 287 | the VirtualBox Graphics Adapter in Device Manager, select "Uninstall", check "Delete the driver software for this device"
|
|---|
| 288 | and click "OK". Once uninstallation is done - in Device Manager go to menu "Action" and select
|
|---|
| 289 | "Scan for hardware changes" to make the propper (Windows default) driver be picked up for the Graphics adapter.
|
|---|
| 290 | </para>
|
|---|
| 291 | </listitem>
|
|---|
| 292 |
|
|---|
| 293 | <listitem>
|
|---|
| 294 | <para>Neither <emphasis>virtio</emphasis> nor <emphasis>Intel PRO/1000
|
|---|
| 295 | </emphasis> drivers for <emphasis role="bold">Windows XP guests
|
|---|
| 296 | </emphasis> support segmentation offloading. Therefore
|
|---|
| 297 | Windows XP guests have slower transmission rates comparing to other
|
|---|
| 298 | guest types. Refer to MS Knowledge base article 842264 for additional
|
|---|
| 299 | information.</para>
|
|---|
| 300 | </listitem>
|
|---|
| 301 |
|
|---|
| 302 | <listitem>
|
|---|
| 303 | <para><emphasis role="bold">Guest Additions for OS/2.</emphasis> Shared
|
|---|
| 304 | folders are not yet supported with OS/2 guests. In addition, seamless
|
|---|
| 305 | windows and automatic guest resizing will probably never be implemented
|
|---|
| 306 | due to inherent limitations of the OS/2 graphics system.</para>
|
|---|
| 307 | </listitem>
|
|---|
| 308 | </itemizedlist>
|
|---|
| 309 | </sect1>
|
|---|
| 310 | </chapter>
|
|---|
