Difference between revisions of "Talk:Xen"
(→Disable IP Tables to not interfere with bridge interfaces: new section)
(→Massive re-write: new section)
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# sysctl -p /etc/sysctl.conf</code>
# sysctl -p /etc/sysctl.conf</code>
Revision as of 18:55, 1 March 2013
For maximum benefit I suggest using the discussion page for page editing collaboration.
Firstly, some things on the current page aren't really clear, imho:
- "The standard arch kernel can be use to boot the domUs."
So, domUs can use the standard kernel?
- "In order for this to work one must add 'xen-blkfront' to the modules array in /etc/mkinitcpio.conf"
On the domUs?
- "The basic idea behind adding a domU is as follows. We must get the domU kernels (...)"
BUT one can also use a standard archlinux kernel? Maybe there is an inconsistency.
- Maybe someone more experienced can explain how to use encrypted (LUKS) filesystems with xen;
- Maybe someone more experienced can add a section on how to use other OSs like Microsoft® Windows&trade.
- I opt to delete the alternative installation method because experienced users can figure this stuff out for themselves and it might be horribly outdated;
-- Voidzero 16:54, 7 May 2010 (EDT)
Thirdly: This is incorrect - was stated before to be a frontend for Xen - it is NOT - it is a frontend for xenserver by citrix
this is also not for xen directly - it is for xen cloud platform which is something different afaik
- xvp is web interface and vnc proxy.
After installing xvp, you need to generate /etc/xvp.conf with xvpdiscover tool and adjust your web server for using /srv/http/xvpweb/.
-- Friesoft 19:01, 23 May 2010 (EDT)
Old section about build failures with dom0 kernel 2.6.31:
Please note: At the time of this writing (23.5.2010) the current version uses a patched kernel version 2.6.31, which won't compile using gcc 4.5.
The problem can be worked around by temporarily downgrading gcc and gcc-libs to version 4.4.3. It may also be needed to build the gmp4 package. You can possibly find gcc-4.4.3 and gcc-libs-4.4.3 on ARM (see Downgrading Packages)
pacman -Ud gcc-* yaourt -S gmp4 # not sure if this is really needed
Note: this didn't work for me (friesoft, 23.5.2010)
- 1 necessary modules on Dom0
- 2 GRUB menu entry outdated
- 3 The standard i686 kernel cannot be used as Dom0 kernel
- 4 Suggestions to make this easier to read
- 5 Need to install bridge-utils to avoid an error on boot
- 6 Article HORRIBLY Outdated!
- 7 Disable IP Tables to not interfere with bridge interfaces
- 8 Massive re-write
necessary modules on Dom0
You need to load xen-blkback in Dom0 for /dev/xvda* devices. If you didn't load it, the DomUs won't find the device for the root file systems.
Similarly, you need to load xen_netback for the network connections, else xm create will pause for quite a while and then abort with a message that it could not configure vif.
After struggling with the apparently outdated install info, I finally managed to dredge up this tidbit: https://bbs.archlinux.org/viewtopic.php?id=133220
The current instructions make it seem as though the AUR xen package will put a new kernel & img in /boot with Dom0 in the name. This is apparently not the case, as it seems to just re-use the existing kernel files (at least in x64 installs). Any chance someone more familiar with the subject could update the install instructions? Zootboy 23:39, 11 January 2012 (EST)
The standard i686 kernel cannot be used as Dom0 kernel
- This is true. The regular x86 (i686) Arch Kernel does not have Xen Dom0 support compiled in. I know that the x64 Kernel does have Dom0 support compiled in by default, and users are strongly encouraged to run Xen on a 64-bit host machine. It's good to have this section, but it should probably be reworked to explain better which Kernels have Xen Dom0 support and why. (I believe the LTS Kernel may have Dom0 compiled in the i686 version, but I'm not sure and I'm having trouble finding where I read that.) Zootboy (talk) 00:05, 28 May 2012 (UTC)
Suggestions to make this easier to read
I think we should add guidance to add xencommons & xend to rc.d to run xend on startup.
Mentioning pv-grub (far superior to pygrub, security wise) is also probably a good plan.
Luceo 23.49, 21st July 2012 (UTC)
Need to install bridge-utils to avoid an error on boot
At least I think that's the correct method, worked for me. Unless someone says otherwise, I will stop back and add that at some point.
- Yes, bridge-utils are necessary for networking to work properly in Xen. Zootboy (talk) 17:08, 4 September 2012 (UTC)
Article HORRIBLY Outdated!
It is NOT possible, to get a workign Xen running with this article! As with many other wiki-articles, since the recent changes in arch linux none of them is an appropiate walkthrough anymore.
Is the following correct for syslinux? Dom0 boots with this here at least
(You need to have mboot.c32 copied into /boot/syslinux/ for these examples.)
Add the following to your /boot/syslinux/syslinux.cfg
LABEL xen MENU LABEL Arch Xen KERNEL mboot.c32 APPEND ../xen-X.Y.Z.gz --- ../vmlinuz-linux console=tty0 root=/dev/sdaX ro -- ../initramfs-linux.img
An example to run Xen on a LUKS encrypted LVM host
LABEL xen MENU LABEL Arch Xen KERNEL mboot.c32 APPEND ../xen-X.Y.Z.gz --- ../vmlinuz-linux console=tty0 cryptdevice=/dev/sdaX:main root=/dev/mapper/main-root ro -- ../initramfs-linux.img
Disable IP Tables to not interfere with bridge interfaces
By default the bridge interfaces created will be filtered using the kernel netfilter code preventing certain packets (like broadcasts) from reaching the DomUs during operation. This makes things like a DomU running DHCPd impossible.
This resolves the problem:
# cat >> /etc/sysctl.conf <<EOF net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 EOF # sysctl -p /etc/sysctl.conf
Just finished a huge re-write of this whole article in my attempt to bring it up to date. For those who are curious: I stripped out the Debian guest instructions because this is the Archwiki. There are links on the Xen wiki for installing Debian. In its place, I put in my own instructions for creating an Arch guest. I also stripped out the instructions for building from source as there are several AUR packages that basically do all the same things anyway. Seeing as you have to build from source when you install Xen from the AUR, it seemed redundant. There are Xen AUR packages for current stable (4.2 atm) and bleeding edge unstable (4.3-unstable atm). That should be sufficient for most cases, so I saw no need for manual compilation instructions.
As an aside, I also seem to recall having to create the /var/lib/xen directory manually. I didn't put it in the article as I couldn't verify that it was still necessary. Zootboy (talk) 18:55, 1 March 2013 (UTC)