As ebuilds for Xen are now in Portage (see bug #70161), we should make a guide on how to set up Xen under Gentoo. I have used it some (quite long) time ago and will use it in the future and I can play with it if noone else wants to practice her/his writing skills.
There is one guide at www.gentoo-wiki.com which we could modify and adopt as our own.
The talk about Rollback network bridge at http://gentoo-wiki.com/Talk:HOWTO_Xen_and_Gentoo is very important to get networking to work. Please see bug: http://bugs.gentoo.org/show_bug.cgi?id=111684 too.
We should probably mark this RESO LATER, as no one is willing to write anything about it, or else know one knows how to set it up, or doesn't remember, or can't be bothered to turn in a minimal set of instructions. If anyone can help, the GDP can write GuideXML and handle the coding; we just need a guide to work from in any format. Otherwise, I think this will be RESO LATERed soon. No progress in a year.
Created attachment 101602 [details] /doc/en/draft/xen.xml A first blurb about Xen (ends by rebooting to the Xenified kernel). COmments are welcome. The rendered version can be seen at http://gentoo.basa.flaska.net/doc/en/draft/xen.xml (can be broken sometimes, especially when I edit that file :) ).
Great, great doc so far. Patch will be attached shortly with comments. :)
Created attachment 102579 [details, diff] xen.xml.patch Patch with some minor corrections to the doc, including English, spelling, coding style, etc. Note that you may want to interactively merge some of the changes, as I deleted your <note> on the lilo stuff. For that, my suggestion is to not even bother with proper lilo setup; grub is way better, and is the standard bootloader in all our docs anyway. lilo users who still use that ancient POS (:p) know how to setup their stuff anyway. ;) Only thing I didn't really poke at was all the FIXME and TODO sections; there are a few <impo>s and <p>s, including a troubleshooting FIXME at the end, and one <comment>(FIXME)</comment> that I guess still need to be written. Other than these areas that need content, this is a really, really great doc. Good work, Jan. :)
"(You usually want your domUs to be able to access some kind of storage :) )" Don't remove the smiley :). As it's quite obvious that you probably want to access your data, either remove the comment completely or just keep it as-is. No need to add parentheses around "FIXME" comments :). Thanks for your review and patch and volunteering to receive every bugmail twice by reassigning. I'll merge most of your changes in next few days (at least I hope I'll manage to do that).
(In reply to comment #7) > "(You usually want your domUs to be able to access some kind of storage :) )" > > Don't remove the smiley :). As it's quite obvious that you probably want to > access your data, either remove the comment completely or just keep it as-is. Oops. I think I saw that as just an extra parenthesis typo and deleted it. simleys++. > No need to add parentheses around "FIXME" comments :). But it makes them so much more special! :p > Thanks for your review and patch and volunteering to receive every bugmail > twice by reassigning. Bugzilla mail++ > I'll merge most of your changes in next few days (at least I hope I'll manage > to do that). Sounds good. If you want to take the bug yourself, you can; I just grabbed it because I like the doc. And since I like to work with docs that I like...well, you've written a good doc, so there. :)
Jan is a big boy; he can take care of his own bugs. I'm willing to help out making the English better as usual.
I'm going to take a peek at this as well, I've always wanted to play with Xen a bit :)
Created attachment 125262 [details] Draft on Xen Guide (not finished) First draft on Xen Guide. Still needs work, attaching so that people know I'm working on it :)
(In reply to comment #11) > Created an attachment (id=125262) [edit] > Draft on Xen Guide (not finished) > > First draft on Xen Guide. Still needs work, attaching so that people know I'm > working on it :) > Great! Do you have this in cvs, svn, or better yet git somewhere so I can easily add some stuff?
Not yet, but I'll put it in gentoo/xml/htdocs/doc/en/draft the moment I'm back home (wasn't a dev yet when I put it on this bug).
Looks good, but I have some comments: * we probably don't want to mention -mfpmath=sse -- it might sound like a recommendation :) * after unmasking the packages, it might be a good idea to install them * it might be better to use explicit /boot/xen.gz paths rather than /xen.gz; this way it works for users without spearate /boot partition (and /boot/boot points to /boot anyway) * I probably shouldn't comment on English, but I believe I've spotted some mistakes like extra "the" in "so that it is started automatically the next time you boot" * when I build my Xen kernels, I don't use the original kernel directory for output, I rather use `make O=~/xen-build/dom0 menuconfig`, `make O=~/xen-build/dom0` and then the same, but with O=~/xen-build/domU. Further kernel rebuilds will be faster. * you might want to add that it's possible to use one kernel image for all domains, including dom0 * when creating file-based disks, using `dd ... count=0 seek=2048` results in creating a sparse file. This might be suboptimal for production, but works great for simple testing purposes. * I'd link to example domU configuration in /etc/xen/ directory in addition to providing a simple conf file * In case you're considering talking about the tap:aio: disk backend, please don't. I've seen various sorts of domU kernel panics related to that. * "When selecting the <e>routed</e> approach, the interface inside your unpriviledged domain is connected to a virtual interface on your administrative domain." -- it's true, but might leave an impression that this is not the case when going bridged. Virtual interface exists regardless of how your networking setup looks like. * "On your administrative domain (domain 0), the virtual interface has the same IP address as <path>eth0</path>" -- that isn't true, those two interfaces are "linked together", but they don't have the same IP address. * the following paragraph needs love: In the above example, the interface will be created for the unpriviledged domain (in which it will be called <path>eth0</path>) and Xen will link the address 192.168.1.101 with the domain 0 <path>eth0</path> interface through interface <path>veth1</path>. That doesn't mean that the virtual <path>eth0</path> interface will automatically have IP 192.168.1.101 assigned to it, but rather that, if you don't give it that IP, it will not be connected with the administrative domain and thus cannot be reached. - "Xen will link the address 192.168.1.101 with the domain 0 <path>eth0</path>" is wrong or misleading. - I can't parse the last sentence
Created attachment 125875 [details] Xen Guide (updated) Full Xen Guide, with some of Jan's comments updated. Stored the bug instead of draft/ because I don't have CVS access atm (only at home).
Created attachment 125954 [details, diff] Add menuconfig listings Here is a quick patch against the current guide posted here that adds menuconfig dialogs for the required kernel options. I'll rework the text in the section to go along with this once I get around to getting commit access to the guide in cvs so I don't have to bother with tons of patches.
Michael If you want the guide can reside in /proj/en/kernel or so for a while (so that you can do the necessary changes yourself as well) unless you're already in the process of gaining CVS access to xml/htdocs/doc/en?
(In reply to comment #17) > Michael > > If you want the guide can reside in /proj/en/kernel or so for a while (so that > you can do the necessary changes yourself as well) unless you're already in the > process of gaining CVS access to xml/htdocs/doc/en? > I haven't even looked into getting access to the xml/htdocs/doc/en directory yet so I guess dropping it under kernel for now would work. In any case I'm going to be busy with OSCON for the few days so I probably won't actually have anything to commit until next week. Thanks :-)
No sweat. I've currently kept it in doc/en/draft because that gives me free access to commit further. Once you get around to dedicate some/more time to it, you're free to put it in proj/en/kernel (or proj/en/xen if its worth a new project, guess not) and give me a hurl so that I can drop it from draft. Dunno if it really belongs there, but I don't mind - as long as the users will eventually get it :)
I'm currently struggling to get Xen's bridging up and running, I hope to get this over with quickly. If that works I'll probably put it online (in /doc/en/).
Bridging works, my issue was that I don't want to bridge my default interface (eth1) but eth0 and somehow it collided. Of course, the documentation is updated with enough information. http://www.gentoo.org/doc/en/draft/xen-guide.xml Please look for misktakes, typos, incorrect information or other. I'm going to put this online at /doc/en after a while. Unlike my previous comments, I don't think this is really a proj/en/kernel document. It's a small document which shouldn't need much updates (I don't want it to become a "HOWTO run everything inside Xen and make coffee with it" guide, just how to setup Xen on Gentoo).
Created attachment 129096 [details, diff] Add a couple notes This patch adds a note about auto-starting guests with xendomains and using block devices for the guests' virtual drive. The guide looks pretty good and the sooner this comes out of drafts the better. I am about to push xen 3.1.0 into the portage tree and I'd like to update the ebuilds to point at this instead of just gentoo-wiki. Thanks for working on this!
Patch edited and included; it is still in draft but won't be for much longer (if I get the time and no further feedback, perhaps even tomorrow).
Just a quick note: We could (should?) include a reference to app-emulation/virt-manager (which is currently ~x86 only, but I'm going to keyword it ~amd64 soon). That is a GTK gui that does the same as "xm top", but in a nice fashion and with mem-set and other options.
Committed to CVS and available online at http://www.gentoo.org/doc/en/xen-guide.xml
Robert, I've opened another bug report (enhancement request) to add references to the guide (see bug #190689) including virt-manager. I'll also definitely take a look at it although I'm personally not that convinced to run X on the administrative domain...
