--- wikisrc/ports/xen/howto.mdwn 2016/12/20 12:53:06 1.112 +++ wikisrc/ports/xen/howto.mdwn 2017/12/15 16:40:59 1.141 @@ -2,7 +2,7 @@ Introduction ============ [![[Xen -screenshot]](http://www.netbsd.org/gallery/in-Action/hubertf-xens.png)](http://www.netbsd.org/gallery/in-Action/hubertf-xen.png) +screenshot]](https://www.netbsd.org/gallery/in-Action/hubertf-xens.png)](https://www.netbsd.org/gallery/in-Action/hubertf-xen.png) Xen is a hypervisor (or virtual machine monitor) for x86 hardware (i686-class or higher), which supports running multiple guest @@ -27,12 +27,19 @@ code for Xen and need not be aware that Attempts to access hardware registers are trapped and emulated. This style is less efficient but can run unmodified guests. -Generally any amd64 machine will work with Xen and PV guests. In -theory i386 computers without amd64 support can be used for Xen <= -4.2, but we have no recent reports of this working (this is a hint). -For HVM guests, the VT or VMX CPU feature (Intel) or SVM/HVM/VT -(amd64) is needed; "cpuctl identify 0" will show this. TODO: Clean up -and check the above features. +Generally any machine that runs NetBSD/amd64 will work with Xen and PV +guests. In theory i386 computers (without x86_64/amd64 support) can +be used for Xen <= 4.2, but we have no recent reports of this working +(this is a hint). For HVM guests, hardware support is needed, but it +is common on recent machines. For Intel CPUs, one needs the VT-x +extension, shown in "cpuctl identify 0" as VMX. For AMD CPUs, one +needs the AMD-V extensions, shown in "cpuctl identify 0" as SVM. +There are further features for IOMMU virtualization, Intel's VT-d and +AMD's AMD-Vi. TODO: Explain whether Xen on NetBSD makes use of these +features. TODO: Review by someone who really understands this. + +Note that a FreeBSD dom0 requires VT-x and VT-d (or equivalent); this +is because the FreeBSD dom0 does not run in PV mode. At boot, the dom0 kernel is loaded as a module with Xen as the kernel. The dom0 can start one or more domUs. (Booting is explained in detail @@ -44,7 +51,7 @@ attempts to address both the case of run and running domUs under it (NetBSD and other), and also running NetBSD as a domU in a VPS. -Some versions of Xen support "PCI passthrough", which means that +Xen 3.1 in pkgsrc supports "PCI passthrough", which means that specific PCI devices can be made available to a specific domU instead of the dom0. This can be useful to let a domU run X11, or access some network interface or other peripheral. @@ -62,9 +69,9 @@ things must be done, guiding the reader path when there are no known good reasons to stray. This HOWTO presumes a basic familiarity with the Xen system -architecture. This HOWTO presumes familiarity with installing NetBSD -on i386/amd64 hardware and installing software from pkgsrc. -See also the [Xen website](http://www.xenproject.org/). +architecture, with installing NetBSD on i386/amd64 hardware, and with +installing software from pkgsrc. See also the [Xen +website](http://www.xenproject.org/). Versions of Xen and NetBSD ========================== @@ -74,6 +81,11 @@ of Xen version and NetBSD version. This which version to choose. Versions not in pkgsrc and older unsupported versions of NetBSD are intentionally ignored. +The term "amd64" is used to refer to both the NetBSD port and to the +hardware architecture on which it runs. (Such hardware is made by +both Intel and AMD, and in 2016 a normal PC has this CPU +architecture.) + Xen --- @@ -82,41 +94,49 @@ xenkernel and xentools. We will refer o but note that both packages must be installed together and must have matching versions. -xenkernel3 provides Xen 3.1. It is no longer maintained by Xen, and the last applied security patch was in -2011. Thus, it should not be used. It supports PCI passthrough, -which is why people use it anyway. Xen 3.1 supports i386, both PAE and -non-PAE. +xenkernel3 provides Xen 3.1. It is no longer maintained by Xen, and +the last applied security patch was in 2011. Thus, it should not be +used. It supports PCI passthrough, which is why people use it anyway. +Xen 3.1 runs on i386 (both non-PAE and PAE) and amd64 hardware. xenkernel33 provides Xen 3.3. It is no longer maintained by Xen, and the last applied security patch was in 2012. Thus, it should not be -used. Xen 3.3 supports i386, but only in PAE mode. There are no good +used. Xen 3.3 runs on i386 PAE and amd64 hardware. There are no good reasons to run this version. xenkernel41 provides Xen 4.1. It is no longer maintained by Xen, but -as of 2016-12 received backported security patches. Xen 4.1 supports -i386, but only in PAE mode. There are no good reasons to run this +as of 2016-12 received backported security patches. Xen 4.1 runs on +i386 PAE and amd64 hardware. There are no good reasons to run this version. +Note that 3.1, 3.3 and 4.1 have been removed from pkgsrc-current, but +are in 2016Q4. They will be removed from this HOWTO sometime after +2017Q1. + xenkernel42 provides Xen 4.2. It is no longer maintained by Xen, but -as of 2016-12 received backported security patches. Xen 4.2 supports -i386, but only in PAE mode. The only reason to run this is if you -need to use xm instead of xl, or if you need to run an i386 dom0 -(because your hardware is i386 only). - -xenkernel45 provides Xen 4.5. It is no longer maintained by Xen, but -as of 2016-12 it received security patches. Xen 4.5 requires an amd64 -dom0, but domUs can be amd64 or i386 PAE. TODO: It is either a -conservative choice or somewhat old. - -xenkernel45 provides Xen 4.6. It is new to pkgsrc in 2016-05. It is -no longer maintained by Xen, but as of 2016-12 it received security -patches. Xen 4.6 requires an amd64 dom0, but domUs can be amd64 or -i386 PAE. TODO: It is either a somewhat aggressive choice or the -standard choice +as of 2016-12 received backported security patches. Xen 4.2 runs on +i386 PAE and amd64 hardware. The only reason to run this is if you +need to use xm instead of xl, or if you need to run on hardware that +supports i386 but not amd64. (This might also be useful if you need +an i386 dom0, if it turns out that an amd64 Xen kernel and an i386 +dom0 is problematic.) + +xenkernel45 provides Xen 4.5. As of 2016-12, security patches were +released by Xen and applied to pkgsrc. Xen 4.5 runs on amd64 hardware +only. While slightly old, 4.5 has been tested and run by others, so +it is the conservative choice. + +xenkernel46 provides Xen 4.6. It is new to pkgsrc as of 2016-05. As +of 2016-12, security patches were released by Xen and applied to +pkgsrc. Xen 4.6 runs on amd64 hardware only For new installations, +4.6 is probably the appropriate choice and it will likely soon be the +standard approach. (If using Ubuntu guests, be sure to have the +xentools46 from December, 2016). -See also the [Xen Security Advisory page](http://xenbits.xen.org/xsa/). +Xen 4.7 (released 2016-06) and 4.8 (released 2016-12) are not yet in +pkgsrc. -Ideally newer versions of Xen will be added to pkgsrc. +See also the [Xen Security Advisory page](http://xenbits.xen.org/xsa/). Note that NetBSD support is called XEN3. It works with Xen 3 and Xen 4 because the hypercall interface has been stable. @@ -127,11 +147,23 @@ Xen command program Early Xen used a program called xm to manipulate the system from the dom0. Starting in 4.1, a replacement program with similar behavior called xl is provided, but it does not work well in 4.1. In 4.2, both -xm and xl work fine. 4.4 is the last version that has xm. You must -choose one or the other, because it affects which daemons you run. -However, the rc.d scripts provided by xentools packages expect a -particular version, and you should use the version used by the -scripts. +xm and xl work fine. 4.4 is the last version that has xm. + +You must make a global choice to use xm or xl, because it affects not +only which command you use, but the command used by rc.d scripts +(specifically xendomains) and which daemons should be run. The +xentools packages provide xm for 3.1, 3.3 and 4.1 and xl for 4.2 and up. + +In 4.2, you can choose to use xm by simply changing the ctl_command +variable and setting xend=YES in rc.conf. + +With xl, virtual devices are configured in parallel, which can cause +problems if they are written assuming serial operation (e.g., updating +firewall rules without explicit locking). There is now locking for +the provided scripts, which works for normal casses (e.g, file-backed +xbd, where a vnd must be allocated). But, as of 201612, it has not +been adequately tested for a complex custom setup with a large number +of interfaces. NetBSD ------ @@ -139,10 +171,15 @@ NetBSD The netbsd-6, netbsd-7, and -current branches are all reasonable choices, with more or less the same considerations for non-Xen use. Therefore, netbsd-7 is recommended as the stable version of the most -recent release for production use. For those wanting to learn Xen or -without production stability concerns, netbsd-7 is still likely most -appropriate, but -current is also a reasonable choice. Xen runs fine -on netbsd-5, but the xentools packages are likely difficult to build. +recent release for production use. In addition, netbsd-7 and -current +have a important scheduler fix (in November of 2015) affecting +contention between dom0 and domUs; see +https://releng.netbsd.org/cgi-bin/req-7.cgi?show=1040 for a +description. For those wanting to learn Xen or without production +stability concerns, netbsd-7 is still likely most appropriate, but +-current is also a reasonable choice. (Xen runs ok on netbsd-5, but +the xentools packages are likely difficult to build, and netbsd-5 is +not supported.) As of NetBSD 6, a NetBSD domU will support multiple vcpus. There is no SMP support for NetBSD as dom0. (The dom0 itself doesn't really @@ -152,30 +189,43 @@ when using a dom0 as a normal computer.) Architecture ------------ -Xen itself can run on i386 (Xen < 3.1) or amd64 machines (all Xen +Xen itself can run on i386 (Xen < 4.2) or amd64 hardware (all Xen versions). (Practically, almost any computer where one would want to run Xen today supports amd64.) -Xen, the dom0 kernel, and each domU kernel can be either i386 or -amd64. When building a xenkernel package, one obtains i386 on an i386 -host, and amd64 on an amd64 host. If the Xen kernel is i386, then the -dom0 kernel and all domU kernels must be i386. With an amd64 Xen -kernel, an amd64 dom0 kernel is known to work, and an i386PAE dom0 -kernel should in theory work. An amd64 Xen/dom0 is known to support -both i386PAE and amd64 domUs. - -i386 dom0 and domU kernels must be PAE (except for Xen 3.1); these are -built by default. (Note that emacs (at least) fails if run on i386 -with PAE when built without, and vice versa, presumably due to bugs in -the undump code.) - -Because of the above, the standard approach is to use amd64 for the -dom0. - -Xen 4.2 is the last version to support i386 as a host. TODO: Clarify -if this is about the CPU, the Xen kernel, or the dom0 kernel having to -be amd64. - +Xen, the dom0 system, and each domU system can be either i386 or +amd64. When building a xenkernel package, one obtains an i386 Xen +kernel on an i386 host, and an amd64 Xen kernel on an amd64 host. If +the Xen kernel is i386, then the dom0 kernel and all domU kernels must +be i386. With an amd64 Xen kernel, an amd64 dom0 kernel is known to +work, and an i386 dom0 kernel should in theory work. An amd64 +Xen/dom0 is known to support both i386 and amd64 domUs. + +i386 dom0 and domU kernels must be PAE (except for an i386 Xen 3.1 +kernel, where one can use non-PAE for dom0 and all domUs); PAE kernels +are included in the NetBSD default build. (Note that emacs (at least) +fails if run on i386 with PAE when built without, and vice versa, +presumably due to bugs in the undump code.) + +Because of the above, the standard approach is to use an amd64 Xen +kernel and NetBSD/amd64 for the dom0. For domUs, NetBSD/i386 (with +the PAE kernel) and NetBSD/amd64 are in widespread use, and there is +little to no Xen-specific reason to prefer one over the other. + +Note that to use an i386 dom0 with Xen 4.5 or higher, one must build +(or obtain from pre-built packages) an amd64 Xen kernel and install +that on the system. (One must also use a PAE i386 kernel, but this is +also required with an i386 Xen kernel.). Almost no one in the +NetBSD/Xen community does this, and the standard, well-tested, +approach is to use an amd64 dom0. + +A [posting on +xen-devel](https://lists.xen.org/archives/html/xen-devel/2012-07/msg00085.html) +explained that PV system call overhead was higher on amd64, and thus +there is some notion that i386 guests are faster. It goes on to +caution that the total situation is complex and not entirely +understood. On top of that caution, the post is about Linux, not +NetBSD. TODO: Include link to benchmarks, if someone posts them. Stability --------- @@ -184,7 +234,6 @@ Mostly, NetBSD as a dom0 or domU is quit However, there are some open PRs indicating problems. - [PR 48125](http://gnats.netbsd.org/48125) - - [PR 47720](http://gnats.netbsd.org/47720) Note also that there are issues with sparse vnd(4) instances, but these are not about Xen -- they just are noticed with sparse vnd(4) @@ -198,42 +247,72 @@ xl, the NetBSD 7 stable branch, and to u dom0. Either the i386PAE or amd64 version of NetBSD may be used as domUs. -Build problems --------------- +Because bugs are fixed quite often, and because of Xen security +advisories, it is good to stay up to date with NetBSD (tracking a +stable branch), with the Xen kernel (tracking a Xen version via +pkgsrc), and with the Xen tools. Specifically, NetBSD (-7 and +-current) got an important fix affecting dom0/domU timesharing in +November, 2015, and xentools46 got a fix to enable Ubuntu guests to +boot in December, 2016. -Ideally, all versions of Xen in pkgsrc would build on all versions of -NetBSD on both i386 and amd64. However, that isn't the case. Besides -aging code and aging compilers, qemu (included in xentools for HVM -support) is difficult to build. The following are known to work or FAIL: - - xenkernel3 netbsd-5 amd64 - xentools3 netbsd-5 amd64 - xentools3=hvm netbsd-5 amd64 ???? - xenkernel33 netbsd-5 amd64 - xentools33 netbsd-5 amd64 - xenkernel41 netbsd-5 amd64 - xentools41 netbsd-5 amd64 - xenkernel42 netbsd-5 amd64 - xentools42 netbsd-5 amd64 - - xenkernel3 netbsd-6 i386 FAIL - xentools3 netbsd-6 i386 - xentools3-hvm netbsd-6 i386 FAIL (dependencies fail) - xenkernel33 netbsd-6 i386 - xentools33 netbsd-6 i386 - xenkernel41 netbsd-6 i386 - xentools41 netbsd-6 i386 - xenkernel42 netbsd-6 i386 - xentools42 netbsd-6 i386 *MIXED - - (all 3 and 33 seem to FAIL) - xenkernel41 netbsd-7 i386 - xentools41 netbsd-7 i386 - xenkernel42 netbsd-7 i386 - xentools42 netbsd-7 i386 ??FAIL +Status +------ -(*On netbsd-6 i386, there is a xentools42 in the 2014Q3 official builds, -but it does not build for gdt.) +Ideally, all versions of Xen in pkgsrc would build on all supported +versions of NetBSD/amd64, to the point where this section would be +silly. However, that has not always been the case. Besides aging +code and aging compilers, qemu (included in xentools for HVM support) +is difficult to build. Note that there is intentionally no data for +4.5+ up for i386, and often omits xentools info if the corresponding +kernel fails. + +The following table gives status, with the date last checked +(generally on the most recent quarterly branch). The first code is +"builds" if it builds ok, and "FAIL" for a failure to build. The +second code/date only appears for xenkernel* and is "works" if it runs +ok as a dom0 and can support a domU, and "FAIL" if it won't boot or +run a domU. + + xenkernel3 netbsd-6 i386 FAIL 201612 + xenkernel33 netbsd-6 i386 FAIL 201612 + xenkernel41 netbsd-6 i386 builds 201612 + xenkernel42 netbsd-6 i386 builds 201612 + xentools3 netbsd-6 i386 FAIL 201612 + xentools33 netbsd-6 i386 FAIL 201612 + xentools41 netbsd-6 i386 builds 201612 + xentools42 netbsd-6 i386 FAIL 201612 + + xenkernel3 netbsd-7 i386 FAIL 201412 + xenkernel33 netbsd-7 i386 FAIL 201412 + xenkernel41 netbsd-7 i386 builds 201412 + xenkernel42 netbsd-7 i386 builds 201412 + xentools41 netbsd-7 i386 builds 201412 + xentools42 netbsd-7 i386 ??FAIL 201412 + + xenkernel3 netbsd-6 amd64 FAIL 201612 + xenkernel33 netbsd-6 amd64 FAIL 201612 + xenkernel41 netbsd-6 amd64 builds 201612 works 201612 + xenkernel42 netbsd-6 amd64 builds 201612 works 201612 + xenkernel45 netbsd-6 amd64 builds 201612 + xenkernel46 netbsd-6 amd64 builds 201612 + xentools41 netbsd-6 amd64 builds 201612 + xentools42 netbsd-6 amd64 builds 201612 + xentools45 netbsd-6 amd64 builds 201612 + xentools46 netbsd-6 amd64 FAIL 201612 + + xenkernel3 netbsd-7 amd64 builds 201612 + xenkernel33 netbsd-7 amd64 builds 201612 + xenkernel41 netbsd-7 amd64 builds 201612 + xenkernel42 netbsd-7 amd64 builds 201612 + xenkernel45 netbsd-7 amd64 builds 201612 + xenkernel46 netbsd-7 amd64 builds 201612 + xentools3 netbsd-7 amd64 builds 201612 + xentools3-hvm netbsd-7 amd64 builds 201612 + xentools33 netbsd-7 amd64 FAIL 201612 + xentools41 netbsd-7 amd64 builds 201612 + xentools42 netbsd-7 amd64 builds 201612 + xentools45 netbsd-7 amd64 builds 201612 + xentools46 netbsd-7 amd64 builds 201612 NetBSD as a dom0 ================ @@ -248,7 +327,10 @@ configuration. For experimenting with Xen, a machine with as little as 1G of RAM and 100G of disk can work. For running many domUs in productions, far -more will be needed. +more will be needed; e.g. 4-8G and 1T of disk is reasonable for a +half-dozen domUs of 512M and 32G each. Basically, the RAM and disk +have to be bigger than the sum of the RAM/disk needs of the dom0 and +all the domUs. Styles of dom0 operation ------------------------ @@ -271,7 +353,7 @@ Xen daemons when not running Xen. Note that NetBSD as dom0 does not support multiple CPUs. This will limit the performance of the Xen/dom0 workstation approach. In theory the only issue is that the "backend drivers" are not yet MPSAFE: - http://mail-index.netbsd.org/netbsd-users/2014/08/29/msg015195.html + https://mail-index.netbsd.org/netbsd-users/2014/08/29/msg015195.html Installation of NetBSD ---------------------- @@ -313,9 +395,11 @@ Installation of Xen ------------------- In the dom0, install sysutils/xenkernel42 and sysutils/xentools42 from -pkgsrc (or another matching pair). -See [the pkgsrc -documentation](http://www.NetBSD.org/docs/pkgsrc/) for help with pkgsrc. +pkgsrc (or another matching pair). See [the pkgsrc +documentation](https://www.NetBSD.org/docs/pkgsrc/) for help with +pkgsrc. Ensure that your packages are recent; the HOWTO does not +contemplate old builds. + For Xen 3.1, support for HVM guests is in sysutils/xentool3-hvm. More recent versions have HVM support integrated in the main xentools @@ -333,13 +417,13 @@ releasedir/i386/binary/kernel/netbsd-XEN should not use Xen 3.1.) Both xen and the NetBSD kernel may be (and typically are) left compressed. -In a dom0 kernel, kernfs is mandatory for xend to communicate with the -kernel, so ensure that /kern is in fstab. TODO: Say this is default, -or file a PR and give a reference. +In a dom0, kernfs is mandatory for xend to communicate with the +kernel, so ensure that /kern is in fstab. (A standard NetBSD install +should already mount /kern.) Because you already installed NetBSD, you have a working boot setup with an MBR bootblock, either bootxx_ffsv1 or bootxx_ffsv2 at the -beginning of your root file system, /boot present, and likely +beginning of your root file system, have /boot, and likely also /boot.cfg. (If not, fix before continuing!) Add a line to to /boot.cfg to boot Xen. See boot.cfg(5) for an @@ -350,11 +434,16 @@ example. The basic line is which specifies that the dom0 should have 256M, leaving the rest to be allocated for domUs. To use a serial console, use - menu=Xen:load /netbsd-XEN3_DOM0.gz console=com0;multiboot /xen.gz dom0_mem=256M console=com1 com1=9600,8n1 + menu=Xen:load /netbsd-XEN3_DOM0.gz;multiboot /xen.gz dom0_mem=256M console=com1 com1=9600,8n1 which will use the first serial port for Xen (which counts starting -from 1), forcing speed/parity, and also for NetBSD (which counts -starting at 0). In an attempt to add performance, one can also add +from 1, unlike NetBSD which counts starting from 0), forcing +speed/parity. Because the NetBSD command line lacks a +"console=pc" argument, it will use the default "xencons" console device, +which directs the console I/O through Xen to the same console device Xen +itself uses (in this case, the serial port). + +In an attempt to add performance, one can also add dom0_max_vcpus=1 dom0_vcpus_pin @@ -367,8 +456,14 @@ and other than dom0 memory and max_vcpus necessary. As with non-Xen systems, you should have a line to boot /netbsd (a -kernel that works without Xen) and fallback versions of the non-Xen -kernel, Xen, and the dom0 kernel. +kernel that works without Xen). Consider a line to boot /netbsd.ok (a +fallback version of the non-Xen kernel, updated manually when you are +sure /netbsd is ok). Consider also a line to boot fallback versions +of Xen and the dom0 kernel, but note that non-Xen NetBSD can be used +to resolve Xen booting issues. + +Probably you want a default=N line to choose Xen in the absence of +intervention. Now, reboot so that you are running a DOM0 kernel under Xen, rather than GENERIC without Xen. @@ -378,13 +473,14 @@ Using grub (historic) Before NetBSD's native bootloader could support Xen, the use of grub was recommended. If necessary, see the -[old grub information](/ports/xen/howto-grub/). +[old grub information](/ports/xen/howto-grub). The [HowTo on Installing into -RAID-1](http://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html) +RAID-1](https://mail-index.NetBSD.org/port-xen/2006/03/01/0010.html) explains how to set up booting a dom0 with Xen using grub with NetBSD's RAIDframe. (This is obsolete with the use of NetBSD's native -boot.) +boot. Now, just create a system with RAID-1, and alter /boot.cfg as +described above.) Configuring Xen --------------- @@ -397,30 +493,23 @@ There will be no domUs, and none can be to configure the dom0 daemons. The daemons which should be run vary with Xen version and with whether -one is using xm or xl. The Xen 3.1 and 3.3 packages use xm. Xen 4.1 -and higher packages use xl. While is is possible to use xm with some -4.x versions (TODO: 4.1 and 4.2?), the pkgsrc-provided rc.d scripts do -not support this as of 2014-12-26, and thus the HOWTO does not support -it either. (Make sure your packages are reasonably recent.) +one is using xm or xl. The Xen 3.1, 3.3 and 4.1 packages use xm. Xen +4.2 and up packages use xl. To use xm with 4.2, edit xendomains to +use xm instead. -For "xm" (3.1 and 3.3), you should enable xend and xenbackendd (but -note that you should be using 4.x): +For 3.1 and 3.3, you should enable xend and xenbackendd: xend=YES xenbackendd=YES -For "xl" (4.x), you should enabled xend and xencommons (xenstored). -Trying to boot 4.x without xencommons=YES will result in a hang; it is -necessary to hit ^C on the console to let the machine finish booting. -TODO: explain why xend is installed by the package. +For 4.1 and up, you should enable xencommons. Not enabling xencommons +will result in a hang; it is necessary to hit ^C on the console to let +the machine finish booting. If you are using xm (default in 4.1, or +if you changed xendomains in 4.2), you should also enable xend: + xend=YES # only if using xm, and only installed <= 4.2 xencommons=YES -The installation of NetBSD should already have created devices for xen -(xencons, xenevt), but if they are not present, create them: - - cd /dev && sh MAKEDEV xen - TODO: Recommend for/against xen-watchdog. After you have configured the daemons and either started them (in the @@ -447,6 +536,13 @@ make this work, one should not expect to (and thus xencommons). There is currently no reason to expect that this will get fixed any time soon. +### No-longer needed advice about devices + +The installation of NetBSD should already have created devices for xen +(xencons, xenevt, xsd_kva), but if they are not present, create them: + + cd /dev && sh MAKEDEV xen + anita (for testing NetBSD) -------------------------- @@ -549,10 +645,10 @@ Hardware known to work Arguably, this section is misplaced, and there should be a page of hardware that runs NetBSD/amd64 well, with the mostly-well-founded assumption that NetBSD/xen runs fine on any modern hardware that -NetBSD/amd64 runs well on. Until then, we give motherboard/CPU/RAM -triples to aid those choosing a motherboard. Note that Xen systems -usually do not run X, so a listing here does not imply that X works at -all. +NetBSD/amd64 runs well on. Until then, we give motherboard/CPU (and +sometimes RAM) pairs/triples to aid those choosing a motherboard. +Note that Xen systems usually do not run X, so a listing here does not +imply that X works at all. Supermicro X9SRL-F, Xeon E5-1650 v2, 96 GiB ECC Supermicro ??, Atom C2758 (8 core), 32 GiB ECC @@ -561,6 +657,8 @@ all. Older hardware: Intel D915GEV, Pentium4 CPU 3.40GHz, 4GB 533MHz Synchronous DDR2 + INTEL DG33FB, "Intel(R) Core(TM)2 Duo CPU E6850 @ 3.00GHz" + INTEL DG33FB, "Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz" Running Xen under qemu ---------------------- @@ -578,7 +676,7 @@ In 2015-01, the following combination wa dom0 kernel: NetBSD/amd64 6.1.5 Xen tools: xentools42-4.2.5 from pkgsrc -See [PR 47720](http://gnats.netbsd.org/47720) for a problem with dom0 +See [PR 47720](https://gnats.netbsd.org/47720) for a problem with dom0 shutdown. Unprivileged domains (domU) @@ -694,10 +792,10 @@ for the first virtual disk for the domU the file serves two purposes. One is that preallocating the contents improves performance. The other is that vnd on sparse files has failed to work. TODO: give working/notworking NetBSD versions for -sparse vnd. Note that the use of file/vnd for Xen is not really -different than creating a file-backed virtual disk for some other -purpose, except that xentools handles the vnconfig commands. To -create an empty 4G virtual disk, simply do +sparse vnd and gnats reference. Note that the use of file/vnd for Xen +is not really different than creating a file-backed virtual disk for +some other purpose, except that xentools handles the vnconfig +commands. To create an empty 4G virtual disk, simply do dd if=/dev/zero of=foo-xbd0 bs=1m count=4096 @@ -731,6 +829,13 @@ guest, one can create /dev/hda1 in /dev, The third element is "w" for writable disks, and "r" for read-only disks. +Note that NetBSD by default creates only vnd[0123]. If you need more +than 4 total virtual disks at a time, run e.g. "./MAKEDEV vnd4" in the +dom0. + +Note that NetBSD by default creates only xbd[0123]. If you need more +virtual disks in a domU, run e.g. "./MAKEDEV xbd4" in the domU. + Virtual Networking ------------------ @@ -1066,7 +1171,7 @@ DOMU kernel. TODO: Explain how to compile npf into a custom kernel, answering (but note that the problem was caused by not booting the right kernel) [this email to -netbsd-users](http://mail-index.netbsd.org/netbsd-users/2014/12/26/msg015576.html). +netbsd-users](https://mail-index.netbsd.org/netbsd-users/2014/12/26/msg015576.html). TODO items for improving NetBSD/xen =================================== @@ -1081,7 +1186,7 @@ TODO items for improving NetBSD/xen fragsize/blocksize (UFS2 support may be present; the point is to make it so that with any UFS1/UFS2 file system setup that works with NetBSD grub will also work). - See [pkg/40258](http://gnats.netbsd.org/40258). + See [pkg/40258](https://gnats.netbsd.org/40258). * Push patches upstream. * Get UFS2 patches into pvgrub. * Add support for PV ops to a version of /boot, and make it usable as @@ -1092,8 +1197,9 @@ TODO items for improving NetBSD/xen Random pointers =============== -TODO: This section contains links from elsewhere not yet integrated -into the HOWTO. +This section contains links from elsewhere not yet integrated into the +HOWTO, and other guides. * http://www.lumbercartel.ca/library/xen/ * http://pbraun.nethence.com/doc/sysutils/xen_netbsd_dom0.html +* https://gmplib.org/~tege/xen.html