user_BasicConcepts.xml@ 53425

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

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