VirtualBox

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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="BasicConcepts">
5 <title>Configuring virtual machines</title>
6
7 <para>Whereas <xref linkend="Introduction" /> gave you a quick introduction
8 to VirtualBox and how to get your first virtual machine running, the
9 following chapter describes in detail how to configure virtual
10 machines.</para>
11
12 <para>You have considerable latitude in deciding what virtual hardware will
13 be provided to the guest. The virtual hardware can be used for communicating
14 with the host system or with other guests. For instance, if you provide
15 VirtualBox with the image of a CD-ROM in an ISO file, VirtualBox can present
16 this image to a guest system as if it were a physical CD-ROM. Similarly, you
17 can give a guest system access to the real network via its virtual network
18 card, and, if you so choose, give the host system, other guests, or
19 computers on the Internet access to the guest system.</para>
20
21 <sect1 id="guestossupport">
22 <title>Supported guest operating systems</title>
23
24 <para>Since VirtualBox is designed to provide a generic virtualization
25 environment for x86 systems, it may run operating systems of any kind,
26 even those not listed here. However, the focus is to optimize VirtualBox
27 for the following guest systems:</para>
28
29 <para><glosslist>
30 <glossentry>
31 <glossterm>Windows NT 4.0</glossterm>
32
33 <glossdef>
34 <para>All versions, editions and service packs are fully
35 supported; however, there are some issues with older service
36 packs. We recommend to install service pack 6a. Guest Additions
37 are available with a limited feature set.</para>
38 </glossdef>
39 </glossentry>
40
41 <glossentry>
42 <glossterm>Windows 2000 / XP / Server 2003 / Vista / Server 2008 /
43 Windows 7 / Windows 8 / Server 2012</glossterm>
44
45 <glossdef>
46 <para>All versions, editions and service packs are fully supported
47 (including 64-bit versions, under the preconditions listed below).
48 Guest Additions are available.</para>
49 </glossdef>
50 </glossentry>
51
52 <glossentry>
53 <glossterm>DOS / Windows 3.x / 95 / 98 / ME</glossterm>
54
55 <glossdef>
56 <para>Limited testing has been performed. Use beyond legacy
57 installation mechanisms not recommended. No Guest Additions
58 available.</para>
59 </glossdef>
60 </glossentry>
61
62 <glossentry>
63 <glossterm>Linux 2.4</glossterm>
64
65 <glossdef>
66 <para>Limited support.</para>
67 </glossdef>
68 </glossentry>
69
70 <glossentry>
71 <glossterm>Linux 2.6</glossterm>
72
73 <glossdef>
74 <para>All versions/editions are fully supported (32 bits and 64
75 bits). Guest Additions are available.</para>
76
77 <para>We strongly recommend using a Linux kernel version 2.6.13 or
78 higher for better performance.<note>
79 <para>Certain Linux kernel releases have bugs that prevent
80 them from executing in a virtual environment; please see <xref
81 linkend="ts_linux-buggy" /> for details.</para>
82 </note></para>
83 </glossdef>
84 </glossentry>
85
86 <glossentry>
87 <glossterm>Linux 3.x</glossterm>
88
89 <glossdef>
90 <para>All versions/editions are fully supported (32 bits and 64
91 bits). Guest Additions are available.</para>
92 </glossdef>
93 </glossentry>
94
95 <glossentry>
96 <glossterm>Solaris 10 (u6 and higher), Solaris 11 (including Solaris
97 11 Express)</glossterm>
98
99 <glossdef>
100 <para>Fully supported (64 bits, prior to Solaris 11 11/11 also 32 bits).
101 Guest Additions are available.</para>
102 </glossdef>
103 </glossentry>
104
105 <glossentry>
106 <glossterm>FreeBSD</glossterm>
107
108 <glossdef>
109 <para>Requires hardware virtualization to be enabled. Limited
110 support. Guest Additions are not available yet.</para>
111 </glossdef>
112 </glossentry>
113
114 <glossentry>
115 <glossterm>OpenBSD</glossterm>
116
117 <glossdef>
118 <para>Requires hardware virtualization to be enabled. Versions 3.7
119 and later are supported. Guest Additions are not available
120 yet.</para>
121 </glossdef>
122 </glossentry>
123
124 <glossentry>
125 <glossterm>OS/2 Warp 4.5</glossterm>
126
127 <glossdef>
128 <para>Requires hardware virtualization to be enabled. We
129 officially support MCP2 only; other OS/2 versions may or may not
130 work. Guest Additions are available with a limited feature
131 set.<footnote>
132 <para>See <xref linkend="KnownIssues" />.</para>
133 </footnote></para>
134 </glossdef>
135 </glossentry>
136
137 <glossentry>
138 <glossterm>Mac OS X</glossterm>
139
140 <glossdef>
141 <para>VirtualBox 3.2 added experimental support for Mac OS X
142 guests, but this comes with restrictions. Please see the following
143 section as well as <xref linkend="KnownIssues" />.</para>
144 </glossdef>
145 </glossentry>
146 </glosslist></para>
147
148 <sect2 id="intro-macosxguests">
149 <title>Mac OS X guests</title>
150
151 <para>Starting with version 3.2, VirtualBox has experimental support for
152 Mac OS X guests. This allows you to install and execute unmodified
153 versions of Mac OS X on supported host hardware.</para>
154
155 <para>Whereas competing solutions perform modifications to the Mac OS X
156 install DVDs (e.g. different boot loader and replaced files), VirtualBox
157 is the first product to provide the modern PC architecture expected by
158 OS X without requiring any "hacks".</para>
159
160 <para>You should be aware of a number of <emphasis role="bold">important
161 issues</emphasis> before attempting to install a Mac OS X guest:<orderedlist>
162 <listitem>
163 <para>Mac OS X is commercial, licensed software and contains
164 <emphasis role="bold">both license and technical restrictions</emphasis>
165 that limit its use to certain hardware and usage scenarios. It is
166 important that you understand and obey these restrictions.</para>
167
168 <para>In particular, for most versions of Mac OS X, Apple prohibits
169 installing them on non-Apple hardware.</para>
170
171 <para>These license restrictions are also enforced on a technical
172 level. Mac OS X verifies whether it is running on Apple hardware,
173 and most DVDs that that come with Apple hardware even check for an
174 exact model. These restrictions are <emphasis>not</emphasis>
175 circumvented by VirtualBox and continue to apply.</para>
176 </listitem>
177
178 <listitem>
179 <para>Only <emphasis role="bold">CPUs</emphasis> known and tested
180 by Apple are supported. As a result, if your Intel CPU is newer
181 than the build of Mac OS X, or if you have a non-Intel CPU, it will
182 most likely panic during bootup with an "Unsupported CPU"
183 exception. It is generally best to use the Mac OS X DVD that came
184 with your Apple hardware.</para>
185 </listitem>
186
187 <listitem>
188 <para>The Mac OS X installer expects the harddisk to be
189 <emphasis role="bold">partitioned</emphasis> so when it does not
190 offer a selection, you have to launch the Disk Utility from the
191 "Tools" menu and partition the hard disk. Then close the Disk
192 Utility and proceed with the installation.</para>
193 </listitem>
194
195 <listitem>
196 <para>In addition, as Mac OS X support in VirtualBox is currently
197 still experimental, please refer also to <xref linkend="KnownIssues" />.</para>
198 </listitem>
199 </orderedlist></para>
200 </sect2>
201
202 <sect2 id="intro-64bitguests">
203 <title>64-bit guests</title>
204
205 <para>VirtualBox supports 64-bit guest operating systems, even on 32-bit
206 host operating systems,<footnote>
207 <para>64-bit guest support was added with VirtualBox 2.0; support
208 for 64-bit guests on 32-bit hosts was added with VirtualBox
209 2.1.</para>
210 </footnote> provided that the following conditions are
211 met:<orderedlist>
212 <listitem>
213 <para>You need a 64-bit processor with hardware virtualization
214 support (see <xref linkend="hwvirt" />).</para>
215 </listitem>
216
217 <listitem>
218 <para>You must enable hardware virtualization for the particular
219 VM for which you want 64-bit support; software virtualization is
220 not supported for 64-bit VMs.</para>
221 </listitem>
222
223 <listitem>
224 <para>If you want to use 64-bit guest support on a 32-bit host
225 operating system, you must also select a 64-bit operating system
226 for the particular VM. Since supporting 64 bits on 32-bit hosts
227 incurs additional overhead, VirtualBox only enables this support
228 upon explicit request.</para>
229
230 <para>On 64-bit hosts (which typically come with hardware
231 virtualization support), 64-bit guest operating systems are always
232 supported regardless of settings, so you can simply install a
233 64-bit operating system in the guest.</para>
234 </listitem>
235 </orderedlist></para>
236
237 <para><warning>
238 <para>On any host, you should enable the <emphasis role="bold">I/O
239 APIC</emphasis> for virtual machines that you intend to use in
240 64-bit mode. This is especially true for 64-bit Windows VMs. See
241 <xref linkend="settings-general-advanced" />. In addition, for
242 64-bit Windows guests, you should make sure that the VM uses the
243 <emphasis role="bold">Intel networking device</emphasis>, since
244 there is no 64-bit driver support for the AMD PCNet card; see <xref
245 linkend="nichardware" />.</para>
246 </warning></para>
247
248 <para>If you use the "Create VM" wizard of the VirtualBox graphical user
249 interface (see <xref linkend="gui-createvm" />), VirtualBox will
250 automatically use the correct settings for each selected 64-bit
251 operating system type.</para>
252 </sect2>
253 </sect1>
254
255 <sect1>
256 <title>Emulated hardware</title>
257
258 <para>VirtualBox virtualizes nearly all hardware of the host. Depending on
259 a VM's configuration, the guest will see the following virtual
260 hardware:<itemizedlist>
261 <listitem>
262 <para><emphasis role="bold">Input devices.</emphasis> By default,
263 VirtualBox emulates a standard PS/2 keyboard and mouse. These
264 devices are supported by almost all past and present operating
265 systems.</para>
266
267 <para>In addition, VirtualBox can provide virtual USB input devices
268 to avoid having to capture mouse and keyboard, as described in <xref
269 linkend="keyb_mouse_normal" />.</para>
270 </listitem>
271
272 <listitem>
273 <para><emphasis role="bold">Graphics.</emphasis> The VirtualBox
274 graphics device (sometimes referred to as VGA device) is, unlike
275 nearly all other emulated devices, not based on any physical
276 counterpart. It is a simple, synthetic device which provides
277 compatibility with standard VGA and several extended registers used
278 by the VESA BIOS Extensions (VBE).</para>
279 </listitem>
280
281 <listitem>
282 <para><emphasis role="bold">Storage.</emphasis> VirtualBox currently
283 emulates the standard ATA interface found on Intel PIIX3/PIIX4
284 chips, the SATA (AHCI) interface, and two SCSI adapters (LSI Logic
285 and BusLogic); see <xref linkend="harddiskcontrollers" /> for
286 details. Whereas providing one of these would be enough for
287 VirtualBox by itself, this multitude of storage adapters is required
288 for compatibility with other hypervisors. Windows is particularly
289 picky about its boot devices, and migrating VMs between hypervisors
290 is very difficult or impossible if the storage controllers are
291 different.</para>
292 </listitem>
293
294 <listitem>
295 <para><emphasis role="bold">Networking.</emphasis> See <xref
296 linkend="nichardware" />.</para>
297 </listitem>
298
299 <listitem>
300 <para><emphasis role="bold">USB.</emphasis> VirtualBox emulates three
301 USB host controllers: xHCI, EHCI, and OHCI. While xHCI handles all USB
302 transfer speeds, only guest operating systems released approximately
303 after 2011 support xHCI. Note that for Windows 7 guests, 3rd party
304 drivers must be installed for xHCI support.</para>
305 <para>
306 Older operating systems typically support OHCI and EHCI. The two
307 controllers are needed because OHCI only handles USB low- and full-speed
308 devices (both USB 1.x and 2.0), while EHCI only handles high-speed
309 devices (USB 2.0 only).</para>
310 <para>
311 The emulated USB controllers do not
312 communicate directly with devices on the host but rather with a
313 virtual USB layer which abstracts the USB protocol and allows the
314 use of remote USB devices.</para>
315 </listitem>
316
317 <listitem>
318 <para><emphasis role="bold">Audio.</emphasis> See <xref
319 linkend="settings-audio" />.</para>
320 </listitem>
321 </itemizedlist></para>
322 </sect1>
323
324 <sect1 id="generalsettings">
325 <title>General settings</title>
326
327 <para>In the Settings window, under "General", you can configure the most
328 fundamental aspects of the virtual machine such as memory and essential
329 hardware. There are three tabs, "Basic", "Advanced" and
330 "Description".</para>
331
332 <sect2>
333 <title>"Basic" tab</title>
334
335 <para>Under the "Basic" tab of the "General" settings category, you can
336 find these settings:</para>
337
338 <glosslist>
339 <glossentry>
340 <glossterm>Name</glossterm>
341
342 <glossdef>
343 <para>The name under which the VM is shown in the list of VMs in
344 the main window. Under this name, VirtualBox also saves the VM's
345 configuration files. By changing the name, VirtualBox renames
346 these files as well. As a result, you can only use characters
347 which are allowed in your host operating system's file
348 names.</para>
349
350 <para>Note that internally, VirtualBox uses unique identifiers
351 (UUIDs) to identify virtual machines. You can display these with
352 <computeroutput>VBoxManage</computeroutput>.</para>
353 </glossdef>
354 </glossentry>
355
356 <glossentry>
357 <glossterm>Operating system / version</glossterm>
358
359 <glossdef>
360 <para>The type of the guest operating system that is (or will be)
361 installed in the VM. This is the same setting that was specified
362 in the "New Virtual Machine" wizard, as described in <xref
363 linkend="gui-createvm" />.</para>
364
365 <para>Whereas the default settings of a newly created VM depend on
366 the selected operating system type, changing the type later has no
367 effect on VM settings; this value is then purely informational and
368 decorative.</para>
369 </glossdef>
370 </glossentry>
371 </glosslist>
372 </sect2>
373
374 <sect2 id="settings-general-advanced">
375 <title>"Advanced" tab</title>
376
377 <para><glosslist>
378 <glossentry>
379 <glossterm>Snapshot Folder</glossterm>
380
381 <glossdef>
382 <para>By default, VirtualBox saves snapshot data together with
383 your other VirtualBox configuration data; see <xref
384 linkend="vboxconfigdata" />. With this setting, you can specify
385 any other folder for each VM.</para>
386 </glossdef>
387 </glossentry>
388
389 <glossentry>
390 <glossterm>Shared Clipboard</glossterm>
391
392 <glossdef>
393 <para>You can select here whether the clipboard of the guest
394 operating system should be shared with that of your host. If you
395 select "Bidirectional", then VirtualBox will always make sure
396 that both clipboards contain the same data. If you select "Host
397 to guest" or "Guest to host", then VirtualBox will only ever
398 copy clipboard data in one direction.</para>
399
400 <para>Clipboard sharing requires that the VirtualBox Guest
401 Additions be installed. As a result, this setting has no effect
402 otherwise; see <xref linkend="guestadditions" /> for
403 details.</para>
404
405 <para>The shared clipboard is disabled by default. See
406 <xref linkend="security_clipboard"/> for an explanation. This
407 setting can be changed at any time using the "Shared Clipboard"
408 menu item in the "Devices" menu of the virtual machine.</para>
409 </glossdef>
410 </glossentry>
411
412 <glossentry>
413 <glossterm>Drag'n'Drop</glossterm>
414 <glossdef>
415 <para>This setting allows to enable support for drag'n drop: Select
416 an object (e.g. a file) from the host or guest and directly copy
417 or open it on the guest or host. Multiple per-VM drag'n drop modes
418 allow restricting access in either direction.</para>
419
420 <para>For drag'n drop to work the Guest Additions need to be
421 installed on the guest.</para>
422
423 <note>Drag'n drop is disabled by default. This setting can be
424 changed at any time using the "Drag'n'Drop" menu item in the
425 "Devices" menu of the virtual machine.</note>
426
427 <para>See <xref linkend="guestadd-dnd"/> for more information.</para>
428
429 <footnote><para>Experimental support for drag and drop was added
430 with VirtualBox 4.2.</para></footnote>
431 </glossdef>
432 </glossentry>
433
434 <glossentry>
435 <glossterm>Removable Media</glossterm>
436 <glossdef>
437 <para>If this is checked, VirtualBox will save the state of what
438 media has been mounted between several runs of a virtual machine.</para>
439 </glossdef>
440 </glossentry>
441
442 <glossentry>
443 <glossterm>Mini ToolBar</glossterm>
444 <glossdef>
445 <para>In full screen or seamless mode, VirtualBox can display a
446 small toolbar that contains some of the items that are normally
447 available from the virtual machine's menu bar. This toolbar
448 reduces itself to a small gray line unless you move the mouse
449 over it. With the toolbar, you can return from full screen or
450 seamless mode, control machine execution or enable certain
451 devices. If you don't want to see the toolbar, disable this
452 setting.</para>
453 <para>The second setting allows to show the toolbar at the top
454 of the screen instead of showing it at the bottom.</para>
455 </glossdef>
456 </glossentry>
457 </glosslist></para>
458 </sect2>
459
460 <sect2>
461 <title>"Description" tab</title>
462
463 <para>Here you can enter any description for your virtual machine, if
464 you want. This has no effect on the functionality of the machine, but
465 you may find this space useful to note down things like the
466 configuration of a virtual machine and the software that has been
467 installed into it.</para>
468 <para>To insert a line break into the description text field, press
469 <emphasis>Shift+Enter</emphasis>.</para>
470 </sect2>
471 </sect1>
472
473 <sect1 id="settings-system">
474 <title>System settings</title>
475
476 <para>The "System" category groups various settings that are related to
477 the basic hardware that is presented to the virtual machine.<note>
478 <para>As the activation mechanism of Microsoft Windows is sensitive to
479 hardware changes, if you are changing hardware settings for a Windows
480 guest, some of these changes may trigger a request for another
481 activation with Microsoft.</para>
482 </note></para>
483
484 <sect2 id="settings-motherboard">
485 <title>"Motherboard" tab</title>
486
487 <para>On the "Motherboard" tab, you can influence virtual hardware that
488 would normally be on the motherboard of a real computer.<glosslist>
489 <glossentry>
490 <glossterm>Base memory</glossterm>
491
492 <glossdef>
493 <para>This sets the amount of RAM that is allocated and given to
494 the VM when it is running. The specified amount of memory will
495 be requested from the host operating system, so it must be
496 available or made available as free memory on the host when
497 attempting to start the VM and will not be available to the host
498 while the VM is running. This is the same setting that was
499 specified in the "New Virtual Machine" wizard, as described with
500 guidelines under <xref linkend="gui-createvm" /> above.</para>
501
502 <para>Generally, it is possible to change the memory size after
503 installing the guest operating system (provided you do not
504 reduce the memory to an amount where the operating system would
505 no longer boot).</para>
506 </glossdef>
507 </glossentry>
508
509 <glossentry>
510 <glossterm>Boot order</glossterm>
511
512 <glossdef>
513 <para>This setting determines the order in which the guest
514 operating system will attempt to boot from the various virtual
515 boot devices. Analogous to a real PC's BIOS setting, VirtualBox
516 can tell a guest OS to start from the virtual floppy, the
517 virtual CD/DVD drive, the virtual hard drive (each of these as
518 defined by the other VM settings), the network, or none of
519 these.</para>
520
521 <para>If you select "Network", the VM will attempt to boot from
522 a network via the PXE mechanism. This needs to be configured in
523 detail on the command line; please see <xref
524 linkend="vboxmanage-modifyvm" />.</para>
525 </glossdef>
526 </glossentry>
527
528 <glossentry>
529 <glossterm>Chipset</glossterm>
530
531 <glossdef>
532 <para>Here you can select which chipset will be presented to the
533 virtual machine. Before VirtualBox 4.0, PIIX3 was the only
534 available option here. For modern guest operating systems such
535 as Mac OS X, that old chipset is no longer well supported. As a
536 result, VirtualBox 4.0 introduced an emulation of the more
537 modern ICH9 chipset, which supports PCI express, three PCI
538 buses, PCI-to-PCI bridges and Message Signaled Interrupts
539 (MSI). This allows modern operating systems to address more PCI
540 devices and no longer requires IRQ sharing. Note that the ICH9
541 support is experimental and not recommended for guest operating
542 systems which do not require it.</para>
543 </glossdef>
544 </glossentry>
545
546 <glossentry>
547 <glossterm>Pointing Device</glossterm>
548
549 <glossdef>
550 <para>The default virtual pointing devices for older guests is the
551 traditional PS/2 mouse. If set to <emphasis>USB tablet</emphasis>,
552 VirtualBox reports to the virtual machine that a USB tablet
553 device is present and communicates mouse events to
554 the virtual machine through this device. The third setting is
555 a <emphasis>USB Multi-Touch Tablet</emphasis> which is suited
556 for recent Windows guests.</para>
557
558 <para>Using the virtual USB tablet has the advantage that
559 movements are reported in absolute coordinates (instead of as
560 relative position changes), which allows VirtualBox to translate
561 mouse events over the VM window into tablet events without
562 having to "capture" the mouse in the guest as described in <xref
563 linkend="keyb_mouse_normal" />. This makes using the VM less
564 tedious even if Guest Additions are not installed.<footnote>
565 <para>The virtual USB tablet was added with VirtualBox 3.2.
566 Depending on the guest operating system selected, this is
567 now enabled by default for new virtual machines.</para>
568 </footnote></para>
569 </glossdef>
570 </glossentry>
571 <glossentry>
572 <glossterm>Enable I/O APIC</glossterm>
573
574 <glossdef>
575 <para>Advanced Programmable Interrupt Controllers (APICs) are a
576 newer x86 hardware feature that have replaced old-style
577 Programmable Interrupt Controllers (PICs) in recent years. With
578 an I/O APIC, operating systems can use more than 16 interrupt
579 requests (IRQs) and therefore avoid IRQ sharing for improved
580 reliability.<note>
581 <para>Enabling the I/O APIC is <emphasis>required</emphasis>
582 for 64-bit guest operating systems, especially Windows
583 Vista; it is also required if you want to use more than one
584 virtual CPU in a virtual machine.</para>
585 </note></para>
586
587 <para>However, software support for I/O APICs has been
588 unreliable with some operating systems other than Windows. Also,
589 the use of an I/O APIC slightly increases the overhead of
590 virtualization and therefore slows down the guest OS a
591 little.<warning>
592 <para>All Windows operating systems starting with Windows
593 2000 install different kernels depending on whether an I/O
594 APIC is available. As with ACPI, the I/O APIC therefore
595 <emphasis>must not be turned off after
596 installation</emphasis> of a Windows guest OS. Turning it on
597 after installation will have no effect however.</para>
598 </warning></para>
599 </glossdef>
600 </glossentry>
601
602 <glossentry>
603 <glossterm>Enable EFI</glossterm>
604
605 <glossdef>
606 <para>This enables Extensible Firmware Interface (EFI), which
607 replaces the legacy BIOS and may be useful for certain
608 advanced use cases. Please refer to <xref linkend="efi" /> for
609 details.</para>
610 </glossdef>
611 </glossentry>
612
613 <glossentry>
614 <glossterm>Hardware clock in UTC time</glossterm>
615
616 <glossdef>
617 <para>If checked, VirtualBox will report the system time in UTC
618 format to the guest instead of local (host) time. This affects
619 how the virtual real-time clock (RTC) operates and may be useful
620 for Unix-like guest operating systems, which typically expect
621 the hardware clock to be set to UTC.</para>
622 </glossdef>
623 </glossentry>
624
625 </glosslist></para>
626
627 <para>In addition, you can turn off the <emphasis role="bold">Advanced
628 Configuration and Power Interface (ACPI)</emphasis> which VirtualBox
629 presents to the guest operating system by default. ACPI is the current
630 industry standard to allow operating systems to recognize hardware,
631 configure motherboards and other devices and manage power. As all modern
632 PCs contain this feature and Windows and Linux have been supporting it
633 for years, it is also enabled by default in VirtualBox. It can only be
634 turned off on the command line; see <xref
635 linkend="vboxmanage-modifyvm" />.<warning>
636 <para>All Windows operating systems starting with Windows 2000
637 install different kernels depending on whether ACPI is available, so
638 ACPI <emphasis>must not be turned off</emphasis> after installation
639 of a Windows guest OS. Turning it on after installation will have no
640 effect however.</para>
641 </warning></para>
642 </sect2>
643
644 <sect2 id="settings-processor">
645 <title>"Processor" tab</title>
646
647 <para>On the "Processor" tab, you can set how many virtual <emphasis
648 role="bold">CPU cores</emphasis> the guest operating systems should see.
649 Starting with version 3.0, VirtualBox supports symmetrical
650 multiprocessing (SMP) and can present up to 32 virtual CPU cores to each
651 virtual machine.</para>
652
653 <para>You should not, however, configure virtual machines to use more
654 CPU cores than you have available physically (real cores, no hyperthreads).</para>
655
656 <para>On this tab you can also set the <emphasis role="bold">"CPU execution
657 cap"</emphasis>. This setting
658 limits the amount of time a host CPU spents to emulate a virtual CPU.
659 The default setting is 100% meaning that there is no limitation. A setting
660 of 50% implies a single virtual CPU can use up to 50% of a single host
661 CPU. Note that limiting the execution time of the virtual CPUs may induce
662 guest timing problems.</para>
663
664 <para>In addition, the <emphasis role="bold">"Enable PAE/NX"</emphasis>
665 setting determines whether the PAE and NX capabilities of the host CPU
666 will be exposed to the virtual machine. PAE stands for "Physical Address
667 Extension". Normally, if enabled and supported by the operating system,
668 then even a 32-bit x86 CPU can access more than 4 GB of RAM. This is
669 made possible by adding another 4 bits to memory addresses, so that with
670 36 bits, up to 64 GB can be addressed. Some operating systems (such as
671 Ubuntu Server) require PAE support from the CPU and cannot be run in a
672 virtual machine without it.</para>
673
674 <para>With virtual machines running modern server operating systems,
675 VirtualBox also supports CPU hot-plugging. For details about this,
676 please refer to <xref linkend="cpuhotplug" />.</para>
677 </sect2>
678
679 <sect2>
680 <title>"Acceleration" tab</title>
681
682 <para>On this page, you can determine whether and how VirtualBox should
683 use hardware virtualization extensions that your host CPU may support.
684 This is the case with most CPUs built after 2006.</para>
685
686 <para>You can select for each virtual machine individually whether
687 VirtualBox should use software or hardware virtualization.<footnote>
688 <para>Prior to VirtualBox version 2.2, software virtualization was
689 the default; starting with version 2.2, VirtualBox will enable
690 hardware virtualization by default for new virtual machines that you
691 create. (Existing virtual machines are not automatically changed for
692 compatibility reasons, and the default can of course be changed for
693 each virtual machine.)</para>
694 </footnote></para>
695
696 <para>In most cases, the default settings will be fine; VirtualBox will
697 have picked sensible defaults depending on the operating system that you
698 selected when you created the virtual machine. In certain situations,
699 however, you may want to change these preconfigured defaults.</para>
700
701 <para>Advanced users may be interested in technical details about
702 software vs. hardware virtualization; please see <xref
703 linkend="hwvirt" />.</para>
704
705 <para>If your host's CPU supports the <emphasis role="bold">nested
706 paging</emphasis> (AMD-V) or <emphasis role="bold">EPT</emphasis> (Intel
707 VT-x) features, then you can expect a significant performance increase
708 by enabling nested paging in addition to hardware virtualization. For
709 technical details, see <xref linkend="nestedpaging" />.</para>
710 </sect2>
711 </sect1>
712
713 <sect1 id="settings-display">
714 <title>Display settings</title>
715
716 <glosslist>
717 <glossentry>
718 <glossterm>Video memory size</glossterm>
719
720 <glossdef>
721 <para>This sets the size of the memory provided by the virtual
722 graphics card available to the guest, in MB. As with the main
723 memory, the specified amount will be allocated from the host's
724 resident memory. Based on the amount of video memory, higher
725 resolutions and color depths may be available.</para>
726 <para>The GUI will show a warning if the amount of video memory
727 is too small to be able to switch the VM into full screen mode.
728 The minimum value depends on the number of virtual monitors, the
729 screen resolution and the color depth of the host display as well
730 as of the activation of <emphasis>3D acceleration</emphasis> and
731 <emphasis>2D video acceleration</emphasis>. A rough estimate
732 is (<emphasis>color depth</emphasis> / 8) x
733 <emphasis>vertical pixels</emphasis> x
734 <emphasis>horizontal pixels</emphasis> x
735 <emphasis>number of screens</emphasis> = <emphasis>number of bytes</emphasis>.
736 Like said above, there might be extra memory required for any
737 activated display acceleration setting.</para>
738 </glossdef>
739 </glossentry>
740
741 <glossentry>
742 <glossterm>Monitor count</glossterm>
743
744 <glossdef>
745 <para>With this setting VirtualBox can provide more than one virtual
746 monitor to a virtual machine. If a guest operating system (such as
747 Windows) supports multiple attached monitors, VirtualBox can pretend
748 that multiple virtual monitors are present.<footnote>
749 <para>Multiple monitor support was added with VirtualBox
750 3.2.</para>
751 </footnote> Up to 8 such virtual monitors are supported.</para>
752
753 <para>The output of the multiple monitors will be displayed on the
754 host in multiple VM windows which are running side by side.</para>
755
756 <para>However, in full screen and seamless mode, they will use the
757 available physical monitors attached to the host. As a result, for
758 full screen and seamless modes to work with multiple monitors, you
759 will need at least as many physical monitors as you have virtual
760 monitors configured, or VirtualBox will report an error. You can
761 configure the relationship between guest and host monitors using the
762 view menu by pressing Host key + Home when you are in full screen or
763 seamless mode.</para>
764
765 <para>Please see <xref linkend="KnownIssues" /> also.</para>
766 </glossdef>
767 </glossentry>
768
769 <glossentry>
770 <glossterm>Enable 3D acceleration</glossterm>
771
772 <glossdef>
773 <para>If a virtual machine has Guest Additions installed, you can
774 select here whether the guest should support accelerated 3D
775 graphics. Please refer to <xref linkend="guestadd-3d" /> for
776 details.</para>
777 </glossdef>
778 </glossentry>
779
780 <glossentry>
781 <glossterm>Enable 2D video acceleration</glossterm>
782
783 <glossdef>
784 <para>If a virtual machine with Microsoft Windows has Guest
785 Additions installed, you can select here whether the guest should
786 support accelerated 2D video graphics. Please refer to <xref
787 linkend="guestadd-2d" /> for details.</para>
788 </glossdef>
789 </glossentry>
790
791 <glossentry>
792 <glossterm>Remote display</glossterm>
793
794 <glossdef>
795 <para>Under the "Remote display" tab, if the VirtualBox Remote
796 Display Extension (VRDE) is installed, you can enable the VRDP server
797 that is built into VirtualBox. This allows you to connect to the
798 console of the virtual machine remotely with any standard RDP viewer,
799 such as <computeroutput>mstsc.exe</computeroutput> that comes with
800 Microsoft Windows. On Linux and Solaris systems you can use the
801 standard open-source <computeroutput>rdesktop</computeroutput>
802 program. These features are described in detail in
803 <xref linkend="vrde" />.</para>
804 </glossdef>
805 </glossentry>
806
807 <glossentry>
808 <glossterm>Video Capture</glossterm>
809
810 <glossdef>
811 <para>Under the "Video Capture" tab you can enable video capturing
812 for this VM. Note that this feature can also be enabled/disabled
813 while the VM is executed.</para>
814 </glossdef>
815 </glossentry>
816 </glosslist>
817 </sect1>
818
819 <sect1 id="settings-storage">
820 <title>Storage settings</title>
821
822 <para>The "Storage" category in the VM settings allows you to connect
823 virtual hard disk, CD/DVD and floppy images and drives to your virtual
824 machine.</para>
825
826 <para>In a real PC, so-called "storage controllers" connect physical disk
827 drives to the rest of the computer. Similarly, VirtualBox presents virtual
828 storage controllers to a virtual machine. Under each controller, the
829 virtual devices (hard disks, CD/DVD or floppy drives) attached to the
830 controller are shown.<note>
831 <para>This section can only give you a quick introduction to the
832 VirtualBox storage settings. Since VirtualBox gives you an enormous
833 wealth of options in this area, we have dedicated an entire chapter of
834 this User Manual to explaining all the details: please see <xref
835 linkend="storage" />.</para>
836 </note></para>
837
838 <para>If you have used the "Create VM" wizard to create a machine, you
839 will normally see something like the following:</para>
840
841 <para><mediaobject>
842 <imageobject>
843 <imagedata align="center" fileref="images/vm-settings-harddisk.png"
844 width="10cm" />
845 </imageobject>
846 </mediaobject></para>
847
848 <para>Depending on the guest operating system type that you selected when
849 you created the VM, the typical layout of storage devices in a new VM is
850 as follows:<itemizedlist>
851 <listitem>
852 <para>You will see an <emphasis role="bold">IDE
853 controller,</emphasis> to which a virtual CD/DVD drive has been
854 attached (to the "secondary master" port of the IDE
855 controller).</para>
856 </listitem>
857
858 <listitem>
859 <para>You will also see a <emphasis role="bold">SATA
860 controller,</emphasis> which is a more modern type of storage
861 controller for higher hard disk data throughput, to which the
862 virtual hard disks are attached. Initially you will normally have
863 one such virtual disk, but as you can see in the above screenshot,
864 you can have more than one, each represented by a disk image file
865 (VDI files, in this case).</para>
866 </listitem>
867 </itemizedlist></para>
868
869 <para>If you created your VM with an older version of VirtualBox, the
870 default storage layout may differ. You might then only have an IDE
871 controller to which both the CD/DVD drive and the hard disks have been
872 attached. This might also apply if you selected an older operating system
873 type when you created the VM. Since older operating systems do not support
874 SATA without additional drivers, VirtualBox will make sure that no such
875 devices are present initially. Please see <xref
876 linkend="harddiskcontrollers" /> for additional information.</para>
877
878 <para>VirtualBox also provides a <emphasis role="bold">floppy
879 controller</emphasis>, which is special: you cannot add devices other than
880 floppy drives to it. Virtual floppy drives, like virtual CD/DVD drives,
881 can be connected to either a host floppy drive (if you have one) or a disk
882 image, which in this case must be in RAW format.</para>
883
884 <para>You can modify these media attachments freely. For example, if you
885 wish to copy some files from another virtual disk that you created, you
886 can connect that disk as a second hard disk, as in the above screenshot.
887 You could also add a second virtual CD/DVD drive, or change where these
888 items are attached. The following options are available:<itemizedlist>
889 <listitem>
890 <para>To <emphasis role="bold">add another virtual hard disk, or a
891 CD/DVD or floppy drive,</emphasis> select the storage controller to
892 which it should be added (IDE, SATA, SCSI, SAS, floppy controller)
893 and then click on the "add disk" button below the tree. You can then
894 either select "Add CD/DVD device" or "Add Hard Disk". (If you
895 clicked on a floppy controller, you can add a floppy drive instead.)
896 Alternatively, right-click on the storage controller and select a
897 menu item there.</para>
898
899 <para>On the right part of the window, you can then set the
900 following:<orderedlist>
901 <listitem>
902 <para>You can then select to which <emphasis
903 role="bold">device slot</emphasis> of the controller the
904 virtual disk should be connected to. IDE controllers have four
905 slots which have traditionally been called "primary master",
906 "primary slave", "secondary master" and "secondary slave". By
907 contrast, SATA and SCSI controllers offer you up to 30 slots
908 to which virtual devices can be attached.</para>
909 </listitem>
910
911 <listitem>
912 <para>You can select which <emphasis role="bold">image
913 file</emphasis> to use.<itemizedlist>
914 <listitem>
915 <para>For virtual hard disks, a button with a drop-down
916 list appears on the right, offering you to either select
917 a <emphasis role="bold">virtual hard disk
918 file</emphasis> using a standard file dialog or to
919 <emphasis role="bold">create a new hard disk</emphasis>
920 (image file), which will bring up the "Create new disk"
921 wizard, which was described in <xref
922 linkend="gui-createvm" />.</para>
923
924 <para>For details on the image file types that are
925 supported, please see <xref
926 linkend="vdidetails" />.</para>
927 </listitem>
928
929 <listitem>
930 <para>For virtual CD/DVD drives, the image files will
931 typically be in the standard ISO format instead. Most
932 commonly, you will select this option when installing an
933 operating system from an ISO file that you have obtained
934 from the Internet. For example, most Linux distributions
935 are available in this way.</para>
936
937 <para>For virtual CD/DVD drives, the following
938 additional options are available:</para>
939
940 <para><itemizedlist>
941 <listitem>
942 <para>If you select <emphasis role="bold">"Host
943 drive"</emphasis> from the list, then the physical
944 device of the host computer is connected to the VM,
945 so that the guest operating system can read from and
946 write to your physical device. This is, for
947 instance, useful if you want to install Windows from
948 a real installation CD. In this case, select your
949 host drive from the drop-down list presented.</para>
950
951 <para>If you want to write (burn) CDs or DVDs using
952 the host drive, you need to also enable the
953 <emphasis role="bold">"Passthrough"</emphasis>
954 option; see <xref linkend="storage-cds" />.</para>
955 </listitem>
956
957 <listitem>
958 <para>If you select <emphasis role="bold">"Remove
959 disk from virtual drive",</emphasis> VirtualBox will
960 present an empty CD/DVD drive to the guest into
961 which no media has been inserted.</para>
962 </listitem>
963 </itemizedlist></para>
964 </listitem>
965 </itemizedlist></para>
966 </listitem>
967 </orderedlist></para>
968 </listitem>
969
970 <listitem>
971 <para>To <emphasis role="bold">remove an attachment,</emphasis>
972 select it and click on the "remove" icon at the bottom (or
973 right-click on it and select the menu item).</para>
974 </listitem>
975 </itemizedlist></para>
976
977 <para>Removable media (CD/DVDs and floppies) can be changed while the
978 guest is running. Since the "Settings" dialog is not available at that
979 time, you can also access these settings from the "Devices" menu of your
980 virtual machine window.</para>
981 </sect1>
982
983 <sect1 id="settings-audio">
984 <title>Audio settings</title>
985
986 <para>The "Audio" section in a virtual machine's Settings window
987 determines whether the VM will see a sound card connected, and whether the
988 audio output should be heard on the host system.</para>
989
990 <para>If audio is enabled for a guest, you can choose between the
991 emulation of an Intel AC'97 controller, an Intel HD Audio
992 controller<footnote>
993 <para>Intel HD Audio support was added with VirtualBox 4.0 because
994 Windows 7 (32-bit and 64-bit versions) as well as 64-bit Windows Vista
995 do not support the Intel AC'97 controller.</para>
996 </footnote> or a SoundBlaster 16 card. In any case, you can select what
997 audio driver VirtualBox will use on the host.</para>
998
999 <para>On a Linux host, depending on your host configuration, you can also
1000 select between the OSS, ALSA or the PulseAudio subsystem. On newer Linux
1001 distributions (Fedora 8 and above, Ubuntu 8.04 and above), the PulseAudio
1002 subsystem should be preferred.</para>
1003 </sect1>
1004
1005 <sect1 id="settings-network">
1006 <title>Network settings</title>
1007
1008 <para>The "Network" section in a virtual machine's Settings window allows
1009 you to configure how VirtualBox presents virtual network cards to your VM,
1010 and how they operate.</para>
1011
1012 <para>When you first create a virtual machine, VirtualBox by default
1013 enables one virtual network card and selects the "Network Address
1014 Translation" (NAT) mode for it. This way the guest can connect to the
1015 outside world using the host's networking and the outside world can
1016 connect to services on the guest which you choose to make visible outside
1017 of the virtual machine.</para>
1018
1019 <para>This default setup is good for probably 95% of VirtualBox users.
1020 However, VirtualBox is extremely flexible in how it can virtualize
1021 networking. It supports many virtual network cards per virtual machine,
1022 the first four of which can be configured in detail in the Manager window.
1023 Additional network cards can be configured on the command line with
1024 VBoxManage. </para>
1025
1026 <para>Because of the vast array of options available, we have dedicated an
1027 entire chapter of this manual to discussing networking configuration;
1028 please see <xref linkend="networkingdetails" />.</para>
1029 </sect1>
1030
1031 <sect1 id="serialports">
1032 <title>Serial ports</title>
1033
1034 <para>VirtualBox fully supports virtual serial ports in a virtual machine
1035 in an easy-to-use manner.<footnote>
1036 <para>Serial port support was added with VirtualBox 1.5.</para>
1037 </footnote></para>
1038
1039 <para>Ever since the original IBM PC, personal computers have been
1040 equipped with one or two serial ports (also called COM ports by DOS and
1041 Windows). Serial ports were commonly used with modems, and some
1042 computer mice used to be connected to serial ports before USB became
1043 commonplace.
1044 </para>
1045
1046 <para>While serial ports are no longer as ubiquitous as they used to be,
1047 there are still some important uses left for them. For example, serial
1048 ports can be used to set up a primitive network over a null-modem cable,
1049 in case Ethernet is not available. Also, serial ports are indispensable
1050 for system programmers needing to do kernel debugging, since kernel
1051 debugging software usually interacts with developers over a serial port.
1052 With virtual serial ports, system programmers can do kernel debugging on a
1053 virtual machine instead of needing a real computer to connect to.</para>
1054
1055 <para>If a virtual serial port is enabled, the guest operating system sees
1056 a standard 16550A compatible UART device. Both receiving and transmitting
1057 data is supported. How this virtual serial port is then connected to the
1058 host is configurable, and the details depend on your host operating system.
1059 </para>
1060
1061 <para>You can use either the graphical user interface or the command-line
1062 <computeroutput>VBoxManage</computeroutput> tool to set up virtual serial
1063 ports. For the latter, please refer to <xref
1064 linkend="vboxmanage-modifyvm" />; in that section, look for the
1065 <computeroutput>--uart</computeroutput> and
1066 <computeroutput>--uartmode</computeroutput> options.</para>
1067
1068 <para>In either case, you can configure up to two virtual serial ports per
1069 virtual machine. For each such device, you will need to
1070 determine<orderedlist>
1071 <listitem>
1072 <para>what kind of serial port the virtual machine should see by
1073 selecting an I/O base address and interrupt (IRQ). For these, we
1074 recommend to use the traditional values<footnote>
1075 <para>See, for example, <ulink
1076 url="http://en.wikipedia.org/wiki/COM_(hardware_interface)">http://en.wikipedia.org/wiki/COM_(hardware_interface)</ulink>.</para>
1077 </footnote>, which are:</para>
1078
1079 <para><orderedlist>
1080 <listitem>
1081 <para>COM1: I/O base 0x3F8, IRQ 4</para>
1082 </listitem>
1083
1084 <listitem>
1085 <para>COM2: I/O base 0x2F8, IRQ 3</para>
1086 </listitem>
1087
1088 <listitem>
1089 <para>COM3: I/O base 0x3E8, IRQ 4</para>
1090 </listitem>
1091
1092 <listitem>
1093 <para>COM4: I/O base 0x2E8, IRQ 3</para>
1094 </listitem>
1095 </orderedlist></para>
1096 </listitem>
1097
1098 <listitem>
1099 <para>Then, you will need to determine what this virtual port should
1100 be connected to. For each virtual serial port, you have the
1101 following options:</para>
1102
1103 <para><itemizedlist>
1104 <listitem>
1105 <para>You can elect to have the virtual serial port
1106 "disconnected", which means that the guest will see the
1107 device, but it will behave as if no cable had been connected
1108 to it.</para>
1109 </listitem>
1110
1111 <listitem>
1112 <para>You can connect the virtual serial port to a physical
1113 serial port on your host. (On a Windows host, this will be a
1114 name like <computeroutput>COM1</computeroutput>; on Linux or
1115 Solaris hosts, it will be a device node like
1116 <computeroutput>/dev/ttyS0</computeroutput>). VirtualBox will
1117 then simply redirect all data received from and sent to the
1118 virtual serial port to the physical device.</para>
1119 </listitem>
1120
1121 <listitem>
1122 <para>You can tell VirtualBox to connect the virtual serial
1123 port to a software pipe on the host. This depends on your host
1124 operating system:<itemizedlist>
1125 <listitem>
1126 <para>On a Windows host, data will be sent and received
1127 through a named pipe. The pipe name must be in the format
1128 <computeroutput>\\.\pipe\&lt;name&gt;</computeroutput>
1129 where <computeroutput>&lt;name&gt;</computeroutput> should
1130 identify the virtual machine but may be freely
1131 chosen.</para>
1132 <para>For forwarding serial traffic, you can use a helper
1133 program called VMware Serial Line Gateway, available for
1134 download at
1135 <literal> <ulink
1136 url="http://www.l4ka.org/91.php">http://www.l4ka.org/91.php</ulink>
1137 </literal>. This tool provides a fixed server mode named
1138 pipe at
1139 <computeroutput>\\.\pipe\vmwaredebug</computeroutput>
1140 and connects incoming TCP connections on port 567 with
1141 the named pipe.</para>
1142 </listitem>
1143
1144 <listitem>
1145 <para>On a Mac, Linux or Solaris host, a local
1146 domain socket is used instead. The socket filename must be
1147 chosen such that the user running VirtualBox has
1148 sufficient privileges to create and write to it. The
1149 <computeroutput>/tmp</computeroutput> directory is often a
1150 good candidate.</para>
1151 <para>On Linux there are various tools which can connect
1152 to a local domain socket or create one in server mode. The
1153 most flexible tool is
1154 <computeroutput>socat</computeroutput> and is available
1155 as part of many distributions.</para>
1156 </listitem>
1157 </itemizedlist></para>
1158
1159 <para>In this case, you can configure whether VirtualBox
1160 should create the named pipe (or, on non-Windows hosts, the
1161 local domain socket) itself or whether VirtualBox should
1162 assume that the pipe (or socket) exists already. With the
1163 <computeroutput>VBoxManage</computeroutput> command-line
1164 options, this is referred to as "server" or "client" mode,
1165 respectively.</para>
1166
1167 <para>For a direct connection between two virtual machines
1168 (corresponding to a null-modem cable), simply configure one VM
1169 to create a pipe/socket and another to attach to it.
1170 </para>
1171 </listitem>
1172
1173 <listitem>
1174 <para>You can send the virtual serial port output to a file.
1175 This option is very useful for capturing diagnostic output from
1176 a guest. Any file may be used for this purpose, as long as the
1177 user running VirtualBox has sufficient privileges to create and
1178 write to the file.
1179 </para>
1180 </listitem>
1181 </itemizedlist></para>
1182 </listitem>
1183 </orderedlist>Up to two serial ports can be configured per virtual
1184 machine, but you can pick any port numbers out of the above. However,
1185 serial ports cannot reliably share interrupts; if both ports are to be
1186 used at the same time, they must use different interrupt levels, for
1187 example COM1 and COM2, but not COM1 and COM3.
1188 </para>
1189 </sect1>
1190
1191 <sect1>
1192 <title>USB support</title>
1193
1194 <sect2 id="settings-usb">
1195 <title>USB settings</title>
1196
1197 <para>The "USB" section in a virtual machine's Settings window allows
1198 you to configure VirtualBox's sophisticated USB support.</para>
1199
1200 <para>VirtualBox can allow virtual machines to access the USB devices on
1201 your host directly. To achieve this, VirtualBox presents the guest
1202 operating system with a virtual USB controller. As soon as the guest
1203 system starts using a USB device, it will appear as unavailable on the
1204 host.<note>
1205 <orderedlist>
1206 <listitem>
1207 <para>Be careful with USB devices that are currently in use on
1208 the host! For example, if you allow your guest to connect to
1209 your USB hard disk that is currently mounted on the host, when
1210 the guest is activated, it will be disconnected from the host
1211 without a proper shutdown. This may cause data loss.</para>
1212 </listitem>
1213
1214 <listitem>
1215 <para>Solaris hosts have a few known limitations regarding USB
1216 support; please see <xref linkend="KnownIssues" />.</para>
1217 </listitem>
1218 </orderedlist>
1219 </note></para>
1220
1221 <para>In addition to allowing a guest access to your local USB devices,
1222 VirtualBox even allows your guests to connect to remote USB devices by
1223 use of the VirtualBox Remote Desktop Extension (VRDE). For details about
1224 this, see <xref linkend="usb-over-rdp" />.</para>
1225
1226 <para>In the Settings dialog, you can first configure whether USB is
1227 available in the guest at all, and then choose the level of USB support:
1228 OHCI for USB 1.1, EHCI (which will also enable OHCI) for USB 2.0,
1229 or xHCI for all USB speeds. <note>
1230 <para>The xHCI and EHCI controllers are shipped as a VirtualBox extension
1231 package, which must be installed separately. See <xref
1232 linkend="intro-installing" /> for more information.</para>
1233 </note></para>
1234
1235 <para>When USB support is enabled for a VM, you can determine in
1236 detail which devices are exists on host. You can choose that devices
1237 can be available on guest sytem. To do that you should add "filters" for
1238 chosen devices. In result these devices will disappear in host system and
1239 will appear in guest system.</para>
1240
1241 <para>Clicking on the "+" button to the right of the "USB Device
1242 Filters" window creates a <emphasis role="bold">new filter.</emphasis>
1243 You can give the filter a name (for referencing it later) and specify
1244 the filter criteria. The more criteria you specify, the more precisely
1245 devices will be selected. For instance, if you specify only a vendor ID
1246 of 046d, all devices produced by Logitech will be available to the
1247 guest. If you fill in all fields, on the other hand, the filter will
1248 only apply to a particular device model from a particular vendor, and
1249 not even to other devices of the same type with a different revision and
1250 serial number.</para>
1251
1252 <para>In detail, the following criteria are available:</para>
1253
1254 <orderedlist>
1255 <listitem>
1256 <para><emphasis role="bold">Vendor and product ID.</emphasis> With
1257 USB, each vendor of USB products carries an identification number
1258 that is unique world-wide, the "vendor ID". Similarly, each line of
1259 products is assigned a "product ID" number. Both numbers are
1260 commonly written in hexadecimal (that is, they are composed of the
1261 numbers 0-9 and the letters A-F), and a colon separates the vendor
1262 from the product ID. For example,
1263 <computeroutput>046d:c016</computeroutput> stands for Logitech as a
1264 vendor, and the "M-UV69a Optical Wheel Mouse" product.</para>
1265
1266 <para>Alternatively, you can also specify <emphasis
1267 role="bold">"Manufacturer"</emphasis> and <emphasis
1268 role="bold">"Product"</emphasis> by name.</para>
1269
1270 <para>To list all the USB devices that are connected to your host
1271 machine with their respective vendor and product IDs, you can use
1272 the following command (see <xref linkend="vboxmanage" />): <screen>VBoxManage list usbhost</screen></para>
1273
1274 <para>On Windows, you can also see all USB devices that are attached
1275 to your system in the Device Manager. On Linux, you can use the
1276 <computeroutput>lsusb</computeroutput> command.</para>
1277 </listitem>
1278
1279 <listitem>
1280 <para><emphasis role="bold">Serial number.</emphasis> While vendor
1281 and product ID are already quite specific to identify USB devices,
1282 if you have two identical devices of the same brand and product
1283 line, you will also need their serial numbers to filter them out
1284 correctly.</para>
1285 </listitem>
1286
1287 <listitem>
1288 <para><emphasis role="bold">Remote.</emphasis> This setting
1289 specifies whether the device will be local only, or remote only
1290 (over VRDP), or either.</para>
1291 </listitem>
1292 </orderedlist>
1293
1294 <para>On a Windows host, you will need to unplug and reconnect a USB
1295 device to use it after creating a filter for it.</para>
1296
1297 <para>As an example, you could create a new USB filter and specify a
1298 vendor ID of 046d (Logitech, Inc), a manufacturer index of 1, and "not
1299 remote". Then any USB devices on the host system produced by Logitech,
1300 Inc with a manufacturer index of 1 will be visible to the guest
1301 system.</para>
1302
1303 <para>Several filters can select a single device -- for example, a
1304 filter which selects all Logitech devices, and one which selects a
1305 particular webcam.</para>
1306
1307 <para>You can <emphasis role="bold">deactivate</emphasis> filters
1308 without deleting them by clicking in the checkbox next to the filter
1309 name.</para>
1310 </sect2>
1311
1312 <sect2>
1313 <title>Implementation notes for Windows and Linux hosts</title>
1314
1315 <para>On Windows hosts, a kernel mode device driver provides USB proxy
1316 support. It implements both a USB monitor, which allows VirtualBox to
1317 capture devices when they are plugged in, and a USB device driver to
1318 claim USB devices for a particular virtual machine. As opposed to
1319 VirtualBox versions before 1.4.0, system reboots are no longer necessary
1320 after installing the driver. Also, you no longer need to replug devices
1321 for VirtualBox to claim them.</para>
1322
1323 <para>On newer Linux hosts, VirtualBox accesses USB devices through
1324 special files in the file system. When VirtualBox is installed, these
1325 are made available to all users in the
1326 <computeroutput>vboxusers</computeroutput> system group. In order to be
1327 able to access USB from guest systems, make sure that you are a member
1328 of this group.</para>
1329
1330 <para>On older Linux hosts, USB devices are accessed using the
1331 <computeroutput>usbfs</computeroutput> file system. Therefore, the user
1332 executing VirtualBox needs read and write permission to the USB file
1333 system. Most distributions provide a group (e.g.
1334 <computeroutput>usbusers</computeroutput>) which the VirtualBox user
1335 needs to be added to. Also, VirtualBox can only proxy to virtual
1336 machines USB devices which are not claimed by a Linux host USB driver.
1337 The <computeroutput>Driver=</computeroutput> entry in
1338 <computeroutput>/proc/bus/usb/devices</computeroutput> will show you
1339 which devices are currently claimed. Please refer to <xref
1340 linkend="ts_usb-linux" /> also for details about
1341 <computeroutput>usbfs</computeroutput>.</para>
1342 </sect2>
1343 </sect1>
1344
1345 <sect1>
1346 <title>Shared folders</title>
1347
1348 <para>Shared folders allow you to easily exchange data between a virtual
1349 machine and your host. This feature requires that the VirtualBox Guest
1350 Additions be installed in a virtual machine and is described in detail in
1351 <xref linkend="sharedfolders" />.</para>
1352 </sect1>
1353
1354 <sect1 id="efi">
1355 <title>Alternative firmware (EFI)</title>
1356
1357 <para>Starting with release 3.1, VirtualBox includes experimental support
1358 for the Extensible Firmware Interface (EFI), which is a new industry
1359 standard intended to eventually replace the legacy BIOS as the primary
1360 interface for bootstrapping computers and certain system services
1361 later.</para>
1362
1363 <para>By default, VirtualBox uses the BIOS firmware for virtual machines.
1364 To use EFI for a given virtual machine, you can enable EFI in the
1365 machine's "Settings" dialog (see <xref linkend="settings-motherboard" />).
1366 Alternatively, use the <computeroutput>VBoxManage</computeroutput> command
1367 line interface like this: <screen>VBoxManage modifyvm "VM name" --firmware efi</screen>
1368 To switch back to using the BIOS, use: <screen>VBoxManage modifyvm "VM name" --firmware bios</screen>One
1369 notable user of EFI is Apple's Mac OS X, but recent Linuxes (such as Fedora
1370 11) and Windows (starting with Vista) offer special versions that can be
1371 booted using EFI as well.</para>
1372
1373 <para>Another possible use of EFI in VirtualBox is development and testing
1374 of EFI applications, without booting any OS.</para>
1375
1376 <para>Note that the VirtualBox EFI support is experimental and will be
1377 enhanced as EFI matures and becomes more widespread. While Mac OS X and
1378 Linux guests are known to work fine, Windows guests are currently unable
1379 to boot with the VirtualBox EFI implementation.</para>
1380
1381 <sect2 id="efividmode">
1382 <title>Video modes in EFI</title>
1383
1384 <para>EFI provides two distinct video interfaces: GOP (Graphics Output
1385 Protocol) and UGA (Universal Graphics Adapter). Mac OS X uses GOP, while
1386 Linux tends to use UGA. VirtualBox provides a configuration option to
1387 control the framebuffer size for both interfaces.</para>
1388
1389 <para>To control GOP, use the following
1390 <computeroutput>VBoxManage</computeroutput> command: <screen>VBoxManage setextradata "VM name" VBoxInternal2/EfiGopMode N</screen>
1391 Where N can be one of 0,1,2,3,4,5 referring to the 640x480, 800x600,
1392 1024x768, 1280x1024, 1440x900, 1920x1200 screen resolution respectively.</para>
1393
1394 <para>To change the UGA resolution: <screen>VBoxManage setextradata "VM name" VBoxInternal2/UgaHorizontalResolution 1440
1395VBoxManage setextradata "VM name" VBoxInternal2/UgaVerticalResolution 900</screen></para>
1396
1397 <para>The video mode for both GOP and UGA can only be changed when the
1398 VM is powered off and remains persistent until changed.</para>
1399 </sect2>
1400
1401 <sect2 id="efibootargs">
1402 <title>Specifying boot arguments</title>
1403
1404 <para>It is currently not possible to manipulate EFI variables from within a running guest
1405 (e.g., setting the "boot-args" variable by running the <computeroutput>nvram</computeroutput> tool in a Mac OS X guest will not work).
1406 As an alternative way, "VBoxInternal2/EfiBootArgs" extradata can be passed to a VM in order to set
1407 the "boot-args" variable. To change the "boot-args" EFI variable:
1408 <screen>VBoxManage setextradata "VM name" VBoxInternal2/EfiBootArgs &lt;value&gt;</screen>
1409 </para>
1410 </sect2>
1411
1412 </sect1>
1413</chapter>
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