| 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><emphasis role="bold">Direct 3D support in Windows
|
|---|
| 44 | guests.</emphasis> For this to work, the Guest Additions must be
|
|---|
| 45 | installed in Windows "safe mode". Press F8 when the Windows guest is
|
|---|
| 46 | booting and select "Safe mode", then install the Guest Additions.
|
|---|
| 47 | Otherwise Windows' file protection mechanism will interfere with the
|
|---|
| 48 | replacement DLLs installed by VirtualBox and keep restoring the original
|
|---|
| 49 | Windows system 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 is only able to
|
|---|
| 55 | display a graphical user interface if the user account it is started
|
|---|
| 56 | under, is currently logged in and has a desktop session. Otherwise, the
|
|---|
| 57 | process will not be able to display its user interface.</para>
|
|---|
| 58 |
|
|---|
| 59 | <para>Also, for using accounts without or with an empty password
|
|---|
| 60 | specified, the group policy needs to be changed on the guest. To do so,
|
|---|
| 61 | open the group policy 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">Guest multi-monitor support.</emphasis> This
|
|---|
| 71 | feature is currently only supported with Windows guests.</para>
|
|---|
| 72 | </listitem>
|
|---|
| 73 |
|
|---|
| 74 | <listitem>
|
|---|
| 75 | <para><emphasis role="bold">Deleting the only snapshot with a running VM
|
|---|
| 76 | is not implemented.</emphasis> Trying to perform this operation will
|
|---|
| 77 | result in an error message. This feature will be added in one of the
|
|---|
| 78 | next maintenance releases. It is possible to delete the only snapshot
|
|---|
| 79 | when the VM is not running, e.g. in "poweroff" or "saved" state.</para>
|
|---|
| 80 | </listitem>
|
|---|
| 81 |
|
|---|
| 82 | <listitem>
|
|---|
| 83 | <para><emphasis role="bold">Disabled host I/O caches.</emphasis>
|
|---|
| 84 | Disabling the host I/O cache (see <xref linkend="iocaching" />) will
|
|---|
| 85 | yield poor performance with VHD and sparse VMDK files as these do not
|
|---|
| 86 | currently support asynchronous I/O. This does not apply to VDI files and
|
|---|
| 87 | raw disk/partition VMDK files, which do support async I/O. This
|
|---|
| 88 | restriction will be lifted in a future maintenance update.</para>
|
|---|
| 89 | </listitem>
|
|---|
| 90 |
|
|---|
| 91 | <listitem>
|
|---|
| 92 | <para><emphasis role="bold">Compacting virtual disk images is limited to
|
|---|
| 93 | VDI files.</emphasis> The <code>VBoxManage modifyhd --compact</code>
|
|---|
| 94 | command is currently only implemented for VDI files. At the moment the
|
|---|
| 95 | only way to optimize the size of a virtual disk images in other formats
|
|---|
| 96 | (VMDK, VHD) is to clone the image and then use the cloned image in the
|
|---|
| 97 | VM configuration.</para>
|
|---|
| 98 | </listitem>
|
|---|
| 99 |
|
|---|
| 100 | <listitem>
|
|---|
| 101 | <para><emphasis role="bold">OVF import/export:</emphasis><itemizedlist>
|
|---|
| 102 | <listitem>
|
|---|
| 103 | <para>When importing an OVF that was previously exported by
|
|---|
| 104 | VirtualBox 3.2 or higher which contains a complete VirtualBox
|
|---|
| 105 | machine configuration in the <vbox:Machine> element, some of
|
|---|
| 106 | the import customizations that can be specified (in either the GUI
|
|---|
| 107 | or on the VBoxManage command line) are presently ignored. In
|
|---|
| 108 | particular, customizations of the imported storage configuration
|
|---|
| 109 | are ignored. This will be fixed in the next release.</para>
|
|---|
| 110 | </listitem>
|
|---|
| 111 |
|
|---|
| 112 | <listitem>
|
|---|
| 113 | <para>OVF localization (multiple languages in one OVF file) is not
|
|---|
| 114 | yet supported.</para>
|
|---|
| 115 | </listitem>
|
|---|
| 116 |
|
|---|
| 117 | <listitem>
|
|---|
| 118 | <para>Some OVF sections like StartupSection,
|
|---|
| 119 | DeploymentOptionSection and InstallSection are ignored.</para>
|
|---|
| 120 | </listitem>
|
|---|
| 121 |
|
|---|
| 122 | <listitem>
|
|---|
| 123 | <para>OVF environment documents, including their property sections
|
|---|
| 124 | and appliance configuration with ISO images, are not yet
|
|---|
| 125 | supported.</para>
|
|---|
| 126 | </listitem>
|
|---|
| 127 |
|
|---|
| 128 | <listitem>
|
|---|
| 129 | <para>Remote files via HTTP or other mechanisms are not yet
|
|---|
| 130 | supported.</para>
|
|---|
| 131 | </listitem>
|
|---|
| 132 | </itemizedlist></para>
|
|---|
| 133 | </listitem>
|
|---|
| 134 |
|
|---|
| 135 | <listitem>
|
|---|
| 136 | <para><emphasis role="bold">Seamless mode</emphasis> does not work
|
|---|
| 137 | correctly with Linux guests that have 3D effects enabled (such as with
|
|---|
| 138 | compiz-enabled window managers).</para>
|
|---|
| 139 | </listitem>
|
|---|
| 140 |
|
|---|
| 141 | <listitem>
|
|---|
| 142 | <para><emphasis role="bold">Mac OS X hosts.</emphasis> The following
|
|---|
| 143 | restrictions apply (all of which will be resolved in future
|
|---|
| 144 | versions):<itemizedlist>
|
|---|
| 145 | <listitem>
|
|---|
| 146 | <para>The numlock emulation has not yet been implemented.</para>
|
|---|
| 147 | </listitem>
|
|---|
| 148 |
|
|---|
| 149 | <listitem>
|
|---|
| 150 | <para>The CPU frequency metric is not supported.</para>
|
|---|
| 151 | </listitem>
|
|---|
| 152 |
|
|---|
| 153 | <listitem>
|
|---|
| 154 | <para>3D OpenGL acceleration, in particular with Linux guests that
|
|---|
| 155 | have 3D effects enabled (such as with compiz-enabled window
|
|---|
| 156 | managers).</para>
|
|---|
| 157 | </listitem>
|
|---|
| 158 |
|
|---|
| 159 | <listitem>
|
|---|
| 160 | <para>Memory ballooning is not supported.</para>
|
|---|
| 161 | </listitem>
|
|---|
| 162 | </itemizedlist></para>
|
|---|
| 163 | </listitem>
|
|---|
| 164 |
|
|---|
| 165 | <listitem>
|
|---|
| 166 | <para><emphasis role="bold">Mac OS X Server guests.</emphasis>
|
|---|
| 167 | <itemizedlist>
|
|---|
| 168 | <listitem>
|
|---|
| 169 | <para>Mac OS X Server guests can only run on a certain host
|
|---|
| 170 | hardware. For details about license and host hardware limitations,
|
|---|
| 171 | please see <xref linkend="intro-macosxguests" />.</para>
|
|---|
| 172 | </listitem>
|
|---|
| 173 |
|
|---|
| 174 | <listitem>
|
|---|
| 175 | <para>VirtualBox does not provide Guest Additions for Mac OS X
|
|---|
| 176 | Server at this time.</para>
|
|---|
| 177 | </listitem>
|
|---|
| 178 |
|
|---|
| 179 | <listitem>
|
|---|
| 180 | <para>The graphics resolution currently defaults to 1024x768 as
|
|---|
| 181 | Mac OS X Server falls back to the built-in EFI display support.
|
|---|
| 182 | See <xref linkend="efividmode" /> for more information on how to
|
|---|
| 183 | change EFI video modes.</para>
|
|---|
| 184 | </listitem>
|
|---|
| 185 |
|
|---|
| 186 | <listitem>
|
|---|
| 187 | <para>Even when idle, Mac OS X Server guests currently burn 100%
|
|---|
| 188 | CPU. This is a power management issue that will be addressed in a
|
|---|
| 189 | future release.</para>
|
|---|
| 190 | </listitem>
|
|---|
| 191 |
|
|---|
| 192 | <listitem>
|
|---|
| 193 | <para>Mac OS X Server guests only work with one CPU assigned to
|
|---|
| 194 | the VM. Support for SMP will be provided in a future
|
|---|
| 195 | release.</para>
|
|---|
| 196 | </listitem>
|
|---|
| 197 |
|
|---|
| 198 | <listitem>
|
|---|
| 199 | <para>Depending on your system and version of Mac OS X Server, you
|
|---|
| 200 | might experience guest hangs after some time. This can be fixed by
|
|---|
| 201 | turning off energy saving (set timeout to "Never") in the system
|
|---|
| 202 | preferences.</para>
|
|---|
| 203 | </listitem>
|
|---|
| 204 |
|
|---|
| 205 | <listitem>
|
|---|
| 206 | <para>By default, the VirtualBox EFI enables debug output of the
|
|---|
| 207 | Mac OS X Server kernel to help you diagnose boot problems. Note
|
|---|
| 208 | that there is a lot of output and not all errors are fatal (they
|
|---|
| 209 | would also show on your physical Mac). You can turn off these
|
|---|
| 210 | messages by issuing this command:<screen>VBoxManage setextradata "VM name" "VBoxInternal2/EfiBootArgs" " "</screen>To
|
|---|
| 211 | revert to the previous behavior, use:<screen>VBoxManage setextradata "VM name" "VBoxInternal2/EfiBootArgs" ""</screen></para>
|
|---|
| 212 | </listitem>
|
|---|
| 213 | </itemizedlist></para>
|
|---|
| 214 | </listitem>
|
|---|
| 215 |
|
|---|
| 216 | <listitem>
|
|---|
| 217 | <para><emphasis role="bold">Solaris hosts.</emphasis> The following
|
|---|
| 218 | restrictions apply for OpenSolaris and Solaris 10:<itemizedlist>
|
|---|
| 219 | <listitem>
|
|---|
| 220 | <para>There is no support for USB devices connected to Solaris 10
|
|---|
| 221 | hosts.</para>
|
|---|
| 222 | </listitem>
|
|---|
| 223 |
|
|---|
| 224 | <listitem>
|
|---|
| 225 | <para>USB support on OpenSolaris hosts requires version snv_124 or
|
|---|
| 226 | higher. Webcams and other isochronous devices are known to have
|
|---|
| 227 | poor performance.</para>
|
|---|
| 228 | </listitem>
|
|---|
| 229 |
|
|---|
| 230 | <listitem>
|
|---|
| 231 | <para>No ACPI information (battery status, power source) is
|
|---|
| 232 | reported to the guest.</para>
|
|---|
| 233 | </listitem>
|
|---|
| 234 |
|
|---|
| 235 | <listitem>
|
|---|
| 236 | <para>No support for using wireless adapters with bridged
|
|---|
| 237 | networking.</para>
|
|---|
| 238 | </listitem>
|
|---|
| 239 | </itemizedlist></para>
|
|---|
| 240 | </listitem>
|
|---|
| 241 |
|
|---|
| 242 | <listitem>
|
|---|
| 243 | <para><emphasis role="bold">Guest Additions for OS/2.</emphasis> Shared
|
|---|
| 244 | folders are not yet supported with OS/2 guests. In addition, seamless
|
|---|
| 245 | windows and automatic guest resizing will probably never be implemented
|
|---|
| 246 | due to inherent limitations of the OS/2 graphics system.</para>
|
|---|
| 247 | </listitem>
|
|---|
| 248 | </itemizedlist>
|
|---|
| 249 | </chapter>
|
|---|
