version 1.184, 2020/11/15 14:56:44
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version 1.189, 2020/11/19 13:55:58
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Line 27 xen itself). It also addresses how to r
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Line 27 xen itself). It also addresses how to r
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and how to deal with having a domU in a Xen environment run by someone |
and how to deal with having a domU in a Xen environment run by someone |
else and/or not running NetBSD. |
else and/or not running NetBSD. |
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There are many choices one can make; the HOWTO recommends the standard |
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approach and limits discussion of alternatives in many cases. |
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## Guest Styles |
## Guest Styles |
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Xen supports different styles of guests. |
Xen supports different styles of guests. |
Line 92 Xen Version |Package Name |Xen CPU Suppo
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Line 95 Xen Version |Package Name |Xen CPU Suppo
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See also the [Xen Security Advisory page](http://xenbits.xen.org/xsa/). |
See also the [Xen Security Advisory page](http://xenbits.xen.org/xsa/). |
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Multiprocessor (SMP) support in NetBSD differs depending on the domain: |
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[[!table data=""" |
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Domain |Supports SMP |
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dom0 |No |
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domU |Yes |
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"""]] |
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Note: NetBSD support is called XEN3. However, it does support Xen 4, |
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because the hypercall interface has remained identical. |
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Older Xen had a python-based management tool called xm, now replaced |
Older Xen had a python-based management tool called xm, now replaced |
by xl. |
by xl. |
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Line 115 NetBSD 8 and up support PV and HVM modes
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Line 107 NetBSD 8 and up support PV and HVM modes
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Support for PVHVM and PVH is available only in NetBSD-current. |
Support for PVHVM and PVH is available only in NetBSD-current. |
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# Creating a dom0 |
NetBSD as a dom0 does not run SMP, because some drivers are not yet |
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safe for this. \todo Link to more information about what needs work. |
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NetBSD, when run as a domU, can and does typically run SMP. |
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Note: NetBSD support is called XEN3. However, it does support Xen 4, |
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because the hypercall interface has remained identical. |
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# Creating a NetBSD dom0 |
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In order to install a NetBSD as a dom0, one must first install a normal |
In order to install a NetBSD as a dom0, one must first install a normal |
NetBSD system, and then pivot the install to a dom0 install by changing |
NetBSD system, and then pivot the install to a dom0 install by changing |
Line 129 In 2018-05, trouble booting a dom0 was r
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Line 129 In 2018-05, trouble booting a dom0 was r
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[Install NetBSD/amd64](/guide/inst/) |
[Install NetBSD/amd64](/guide/inst/) |
just as you would if you were not using Xen. |
just as you would if you were not using Xen. |
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Therefore, use the most recent release, or a build from the most recent stable branch. |
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## Installation of Xen |
## Installation of Xen |
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We will consider that you chose to use Xen 4.13, with NetBSD/amd64 as |
Use the most recent version of Xen in pkgsrc, unless the DESCR says that it is not suitable. |
dom0. In the dom0, install xenkernel48 and xentools48 from pkgsrc. |
Therefore, choose 4.13. |
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In the dom0, install xenkernel413 and xentools413 from pkgsrc. |
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Once this is done, install the Xen kernel itself: |
Once this is done, copy the Xen kernel from where pkgsrc puts it to |
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where the boot process will be able to find it: |
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[[!template id=programlisting text=""" |
[[!template id=programlisting text=""" |
# cp /usr/pkg/xen48-kernel/xen.gz / |
# cp -p /usr/pkg/xen413-kernel/xen.gz / |
"""]] |
"""]] |
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Then, place a NetBSD XEN3_DOM0 kernel in the `/` directory. Such kernel |
Then, place a NetBSD XEN3_DOM0 kernel in the `/` directory. Such kernel |
Line 146 can either be compiled manually, or down
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Line 149 can either be compiled manually, or down
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example at: |
example at: |
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[[!template id=programlisting text=""" |
[[!template id=programlisting text=""" |
ftp.netbsd.org/pub/NetBSD/NetBSD-8.0/amd64/binary/kernel/netbsd-XEN3_DOM0.gz |
ftp.netbsd.org/pub/NetBSD/NetBSD-9.1/amd64/binary/kernel/netbsd-XEN3_DOM0.gz |
"""]] |
"""]] |
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Add a line to /boot.cfg to boot Xen: |
Add a line to /boot.cfg to boot Xen: |
Line 156 menu=Xen:load /netbsd-XEN3_DOM0.gz conso
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Line 159 menu=Xen:load /netbsd-XEN3_DOM0.gz conso
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"""]] |
"""]] |
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This specifies that the dom0 should have 512MB of ram, leaving the rest |
This specifies that the dom0 should have 512MB of ram, leaving the rest |
to be allocated for domUs. To use a serial console, use: |
to be allocated for domUs. |
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NB: This says add, not replace, so that you will be able to boot a |
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NetBSD kernel without Xen. Once Xen boots ok, you may want to set it |
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as default. |
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To use a serial console, add settings as follows: |
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[[!template id=filecontent name="/boot.cfg" text=""" |
[[!template id=filecontent name="/boot.cfg" text=""" |
menu=Xen:load /netbsd-XEN3_DOM0.gz;multiboot /xen.gz dom0_mem=512M console=com1 com1=9600,8n1 |
menu=Xen:load /netbsd-XEN3_DOM0.gz;multiboot /xen.gz dom0_mem=512M console=com1 com1=9600,8n1 |
Line 176 more) and to pin that vcpu to a physical
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Line 185 more) and to pin that vcpu to a physical
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and other than dom0 memory and max_vcpus, they are generally not |
and other than dom0 memory and max_vcpus, they are generally not |
necessary. |
necessary. |
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Copy the boot scripts into `/etc/rc.d`: |
Ensure that the boot scripts installed in |
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`/usr/pkg/share/examples/rc.d` are in `/etc/rc.d`, either because you |
[[!template id=programlisting text=""" |
have `PKG_RCD_SCRIPTS=yes`, or manually. (This is not special to Xen, |
# cp /usr/pkg/share/examples/rc.d/xen* /etc/rc.d/ |
but a normal part of pkgsrc usage.) |
"""]] |
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Enable `xencommons`: |
Set `xencommons=YES` in rc.conf: |
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[[!template id=filecontent name="/etc/rc.conf" text=""" |
[[!template id=filecontent name="/etc/rc.conf" text=""" |
xencommons=YES |
xencommons=YES |
"""]] |
"""]] |
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\todo Recommend for/against xen-watchdog. |
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Now, reboot so that you are running a DOM0 kernel under Xen, rather |
Now, reboot so that you are running a DOM0 kernel under Xen, rather |
than GENERIC without Xen. |
than GENERIC without Xen. |
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TODO: Recommend for/against xen-watchdog. |
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Once the reboot is done, use `xl` to inspect Xen's boot messages, |
Once the reboot is done, use `xl` to inspect Xen's boot messages, |
available resources, and running domains. For example: |
available resources, and running domains. For example: |
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Line 219 the state when the new xenstored starts.
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Line 227 the state when the new xenstored starts.
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make this work, one should not expect to be able to restart xenstored |
make this work, one should not expect to be able to restart xenstored |
(and thus xencommons). There is currently no reason to expect that |
(and thus xencommons). There is currently no reason to expect that |
this will get fixed any time soon. |
this will get fixed any time soon. |
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\todo Confirm if this is still true in 2020. |
## anita (for testing NetBSD) |
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With the setup so far, one should be able to run |
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anita (see pkgsrc/misc/py-anita) to test NetBSD releases, by doing (as |
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root, because anita must create a domU): |
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[[!template id=programlisting text=""" |
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anita --vmm=xl test file:///usr/obj/i386/ |
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"""]] |
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## Xen-specific NetBSD issues |
## Xen-specific NetBSD issues |
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Line 244 options as GENERIC. While it is debatab
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Line 243 options as GENERIC. While it is debatab
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bug, users should be aware of this and can simply add missing config |
bug, users should be aware of this and can simply add missing config |
items if desired. |
items if desired. |
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Finally, there have been occasional reports of trouble with X11 |
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servers in NetBSD as a dom0. |
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## Updating Xen in a dom0 |
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Basically, update the xenkernel and xentools packages and copy the new |
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Xen kernel into place, and reboot. This procedure should be usable to |
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update to a new Xen release, but the reader is reminded that having a |
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non-Xen boot methods was recommended earlier. |
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## Updating NetBSD in a dom0 |
## Updating NetBSD in a dom0 |
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This is just like updating NetBSD on bare hardware, assuming the new |
This is just like updating NetBSD on bare hardware, assuming the new |
Line 254 and adjusts `/etc`.
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Line 263 and adjusts `/etc`.
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Note that one must update both the non-Xen kernel typically used for |
Note that one must update both the non-Xen kernel typically used for |
rescue purposes and the DOM0 kernel used with Xen. |
rescue purposes and the DOM0 kernel used with Xen. |
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## Converting from grub to /boot |
## anita (for testing NetBSD) |
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With a NetBSD dom0, even without any domUs, one should be able to run |
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anita (see pkgsrc/misc/py-anita) to test NetBSD releases, by doing (as |
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root, because anita must create a domU): |
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[[!template id=programlisting text=""" |
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anita --vmm=xl test file:///usr/obj/i386/ |
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"""]] |
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## Converting from grub to /boot (historical note) |
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These instructions are provided only to help people using grub, which |
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used to be the normal approach. |
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These instructions were used to convert a system from |
These instructions were used to convert a system from |
grub to /boot. The system was originally installed in February of |
grub to /boot. The system was originally installed in February of |
Line 284 default=1
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Line 306 default=1
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timeout=30 |
timeout=30 |
"""]] |
"""]] |
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## Upgrading Xen versions |
# Unprivileged domains (domU) |
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Minor version upgrades are trivial. Just rebuild/replace the |
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xenkernel version and copy the new xen.gz to `/` (where `/boot.cfg` |
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references it), and reboot. |
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#Unprivileged domains (domU) |
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This section describes general concepts about domUs. It does not |
This section describes general concepts about domUs. It does not |
address specific domU operating systems or how to install them. The |
address specific domU operating systems or how to install them. The |
Line 332 are stored in files and Xen attaches the
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Line 348 are stored in files and Xen attaches the
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dom0 on domain creation. The system treats xbd0 as the boot device |
dom0 on domain creation. The system treats xbd0 as the boot device |
without needing explicit configuration. |
without needing explicit configuration. |
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There is not type line; that implicitly defines a pv domU. |
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By convention, domain config files are kept in `/usr/pkg/etc/xen`. Note |
By convention, domain config files are kept in `/usr/pkg/etc/xen`. Note |
that "xl create" takes the name of a config file, while other commands |
that "xl create" takes the name of a config file, while other commands |
take the name of a domain. |
take the name of a domain. |
Line 400 Note that NetBSD by default creates only
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Line 418 Note that NetBSD by default creates only
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than 4 total virtual disks at a time, run e.g. "./MAKEDEV vnd4" in the |
than 4 total virtual disks at a time, run e.g. "./MAKEDEV vnd4" in the |
dom0. |
dom0. |
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Note that NetBSD by default creates only xbd[0123]. If you need more |
## Virtual Networking |
virtual disks in a domU, run e.g. "./MAKEDEV xbd4" in the domU. |
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Virtual Networking |
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------------------ |
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Xen provides virtual Ethernets, each of which connects the dom0 and a |
Xen provides virtual Ethernets, each of which connects the dom0 and a |
domU. For each virtual network, there is an interface "xvifN.M" in |
domU. For each virtual network, there is an interface "xvifN.M" in |
Line 436 The MAC address specified is the one use
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Line 450 The MAC address specified is the one use
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domain. The interface in dom0 will use this address XOR'd with |
domain. The interface in dom0 will use this address XOR'd with |
00:00:00:01:00:00. Random MAC addresses are assigned if not given. |
00:00:00:01:00:00. Random MAC addresses are assigned if not given. |
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Starting domains automatically |
## Starting domains automatically |
------------------------------ |
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To start domains `domU-netbsd` and `domU-linux` at boot and shut them |
To start domains `domU-netbsd` and `domU-linux` at boot and shut them |
down cleanly on dom0 shutdown, add the following in rc.conf: |
down cleanly on dom0 shutdown, add the following in rc.conf: |
Line 446 down cleanly on dom0 shutdown, add the f
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Line 459 down cleanly on dom0 shutdown, add the f
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xendomains="domU-netbsd domU-linux" |
xendomains="domU-netbsd domU-linux" |
"""]] |
"""]] |
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# Creating a domU |
# domU setup for specific systems |
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Creating domUs is almost entirely independent of operating system. We |
Creating domUs is almost entirely independent of operating system. We |
have already presented the basics of config files. Note that you must |
have already presented the basics of config files in the previous system. |
have already completed the dom0 setup so that "xl list" works. |
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Of course, this section presumes that you have a working dom0. |
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Creating a NetBSD PV domU |
## Creating a NetBSD PV domU |
-------------------------- |
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See the earlier config file, and adjust memory. Decide on how much |
See the earlier config file, and adjust memory. Decide on how much |
storage you will provide, and prepare it (file or LVM). |
storage you will provide, and prepare it (file or LVM). |
Line 462 While the kernel will be obtained from t
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Line 475 While the kernel will be obtained from t
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file should be present in the domU as /netbsd so that tools like |
file should be present in the domU as /netbsd so that tools like |
savecore(8) can work. (This is helpful but not necessary.) |
savecore(8) can work. (This is helpful but not necessary.) |
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The kernel must be specifically for Xen and for use as a domU. The |
The kernel must be specifically built for Xen, to use PV interfacesas |
i386 and amd64 provide the following kernels: |
a domU. NetBSD release builds provide the following kernels: |
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i386 XEN3PAE_DOMU |
i386 XEN3PAE_DOMU |
amd64 XEN3_DOMU |
amd64 XEN3_DOMU |
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This will boot NetBSD, but this is not that useful if the disk is |
This will boot NetBSD, but this is not that useful if the disk is |
empty. One approach is to unpack sets onto the disk outside of xen |
empty. One approach is to unpack sets onto the disk outside of Xen |
(by mounting it, just as you would prepare a physical disk for a |
(by mounting it, just as you would prepare a physical disk for a |
system you can't run the installer on). |
system you can't run the installer on). |
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Line 489 line should be used in the config file.
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Line 502 line should be used in the config file.
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After booting the domain, the option to install via CDROM may be |
After booting the domain, the option to install via CDROM may be |
selected. The CDROM device should be changed to `xbd1d`. |
selected. The CDROM device should be changed to `xbd1d`. |
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Once done installing, "halt -p" the new domain (don't reboot or halt, |
Once done installing, "halt -p" the new domain (don't reboot or halt: |
it would reload the INSTALL_XEN3_DOMU kernel even if you changed the |
it would reload the INSTALL_XEN3_DOMU kernel even if you changed the |
config file), switch the config file back to the XEN3_DOMU kernel, |
config file), switch the config file back to the XEN3_DOMU kernel, |
and start the new domain again. Now it should be able to use "root on |
and start the new domain again. Now it should be able to use "root on |
xbd0a" and you should have a, functional NetBSD domU. |
xbd0a" and you should have a functional NetBSD domU. |
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TODO: check if this is still accurate. |
TODO: check if this is still accurate. |
When the new domain is booting you'll see some warnings about *wscons* |
When the new domain is booting you'll see some warnings about *wscons* |
Line 525 not really a Xen-specific issue, but bec
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Line 538 not really a Xen-specific issue, but bec
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obtained from the dom0, it is far more likely to be out of sync or |
obtained from the dom0, it is far more likely to be out of sync or |
missing with Xen.) |
missing with Xen.) |
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Creating a Linux domU |
Note that NetBSD by default creates only xbd[0123]. If you need more |
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virtual disks in a domU, run e.g. "./MAKEDEV xbd4" in the domU. |
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## Creating a Linux domU |
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Creating unprivileged Linux domains isn't much different from |
Creating unprivileged Linux domains isn't much different from |
unprivileged NetBSD domains, but there are some details to know. |
unprivileged NetBSD domains, but there are some details to know. |
Line 580 Use type='pvh'.
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Line 595 Use type='pvh'.
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\todo Explain where the kernel comes from. |
\todo Explain where the kernel comes from. |
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Creating a Solaris domU |
## Creating a Solaris domU |
----------------------- |
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See possibly outdated |
See possibly outdated |
[Solaris domU instructions](/ports/xen/howto-solaris/). |
[Solaris domU instructions](/ports/xen/howto-solaris/). |
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PCI passthrough: Using PCI devices in guest domains |
## PCI passthrough: Using PCI devices in guest domains |
--------------------------------------------------- |
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NB: PCI passthrough only works on some Xen versions and as of 2020 it |
NB: PCI passthrough only works on some Xen versions and as of 2020 it |
is not clear that it works on any version in pkgsrc. Reports |
is not clear that it works on any version in pkgsrc. Reports |
Line 661 note that only the "xpci" lines are unus
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Line 674 note that only the "xpci" lines are unus
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cd* at scsibus? target ? lun ? # SCSI CD-ROM drives |
cd* at scsibus? target ? lun ? # SCSI CD-ROM drives |
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# Specific Issues |
# Miscellaneous Information |
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## Nesting under Linux KVM |
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It is possible to run a Xen and a NetBSD dom0 under Linux KVM. One |
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can enable virtio in the dom0 for greater speed. |
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## Other nesting |
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In theory, any full emulation should be able to run Xen and a NetBSD |
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dom0. The HOWTO does not currently have information about Xen XVM |
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mode, nvmm, qemu, Virtualbox, etc. |
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## domU |
## NetBSD 5 as domU |
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[NetBSD 5 is known to panic.](http://mail-index.netbsd.org/port-xen/2018/04/17/msg009181.html) |
[NetBSD 5 is known to panic.](http://mail-index.netbsd.org/port-xen/2018/04/17/msg009181.html) |
(However, NetBSD 5 systems should be updated to a supported version.) |
(However, NetBSD 5 systems should be updated to a supported version.) |