I''m working on making a better xen faq. Hopefully I can use it to replace the one we now have on the wiki. I''d love to know what people think really are the most frequently asked questions? I''m going to paw through the mountains of data that is the xen-users archive and see what I see. That should be interesting, but probably not as useful as your opinions. -Dylan _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Dylan Martin wrote:> I''m working on making a better xen faq. Hopefully I can use it to > replace the one we now have on the wiki.Please, don''t start a new one, but improve the one that is there!> > I''d love to know what people think really are the most frequently > asked questions?Hard to say ad-hoc. I think your start looking at the archives is a good one. Add these you think which are not covered in the FAQ, and remove these which are not up to date anymore. (Answers which are still valid but don''t seem frequently asked anymore should stay - they might just not be frequently asked on the list because they are on the FAQ and some people read it. Apart from that, a lot problems I see occuring and reoccuring with Xen, and coming as questions to the list are either: - very strange behaviour of Xen under very special circumstances, like specific (broken) hardware, and very specific setups, together with quite esoteric and hard to debug errors occuring. There are so many versions of Xen out there, and every distribution has their own specific set of patches to Xen and the Xen Linux Kernel(and thesde all are combined with gazillions of different hardware setups), that it''s hard to catch all these problems. - bad error reporting and logging. This is not a documentation problem. I did not run into these problems for a while because I have my fixed setup, but there was times when I found it really bad how errors are reported in Xen: - very first, the logfile where you _might_ find some useful information in ist the one with "debug" in it''s name - which is opposite to usual behaviour. Normally, in debug i''d expect strange stuff only developers understand, and in the normal log, stuff useful for users is saved. Xen is the other way around. - bad error checking and reporting in the userspace tools. Like, for example, if you don''t set qemu_dm right in the config file, instead of getting a decent warning, one just gets a Qemu screen which stays blank. There was some other common misconfiguration that occured sometimes, and resulted in a totally esoteric error message - I forgot it sadly. There might be more of them. - people who don''t read the FAQ, user manual(admittedly outdated and missing a lot of important things, still gives a very good overview of what xen is about), and fail to search mailing lists. Sadly, you won''t catch these with a FAQ, and my attempts to set up a list netiquette where not recognized by XenSource. even if one employee of them told me he wanted to get the netiquette onto the List subscription page. my 2 cents. Henning _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, You''ve probably already got these FAQs on your list, but just in case, here are questions I have either asked myself, or had to look up elsewhere. Not sure if they are all frequently asked, but they all ought to be documented somewhere. Which permutations of bittedness (64/32/32PAE-bit) and type of virtualization (PV/HVM) domU work under each bittedness of dom0 ? In the case of permutations which don''t work, some information about whether it''s a fundamental limitation of the architecture, or whether it''s just an implementation thing likely to be temporary? What is this PAE? (If that''s beyond the scope of xen documentation, then perhaps the answer could be a URL pointing readers elsewhere). How do I tell if my existing CPU/motherboard/chipset is VT compatible? How do I choose a new CPU/motherboard/chipset that is known to be VT compatible? Can I tunnel or otherwise map a particular PCI device to a particular HVM domU? Ditto for PV domU? Can I tunnel or otherwise map a particular USB device to a particular HVM domU? Ditto for PV domU? What are my options, if any, for running accelerated graphics applications (e.g. Google Earth under Windows) within a domU? Can I migrate a hardware-direct OS installation to run as an HVM domU? Ditto for PV? What tools, if any, exist to help with this? How do I send ctrl-alt-del to a domU? How do I change a removable disk mapped to a domU? ( & other questions about functionality provided by the quemu-dm menu.) I can''t get into the qemu-dm menu. Why? Answer: The keystrokes (ctrl+alt+something_i_forget) has to use the _left_ ctrl and alt key. If your keyboard only has the right one (such as a Datahand keyboard), you are out of luck. Can I use an off-the rack Linux kernel for DomU? For PV dom0? What is the status of getting Xen patches into the off-the-rack kernel source, so that they cease to be "special"? Exactly which patches are applied to an off-the-rack kernel to make a Xen kernel? If I want to do the patching myself, where do I download the patches? Any special instructions? [This would be useful for people who want/need to experiment with different kernel revs than the ones provided because, for example, of newer hardware support or bug fixes]. My mouse behaves horribly under HVM windows. Why? (Answer: need usbdevice="tablet" in config file.) Xen startup messages scroll by too fast for me to read. How do I know what errors there were? (Note: xm dmesg is only a partial solution, since the system may not boot up. Slowing it by sending messages to serial doesn''t work on motherboards without a serial port e.g. HP d4600y. So, I don''t think there''s a really good answer to this question until someone adds a "slowmedown" option to the xen grub command line options). What is the role of qemu? Where does it fit into the big picture? If I think of others, I''ll post them here. Derek. On 7/10/07, Henning Sprang <henning_sprang@gmx.de> wrote:> Dylan Martin wrote: > > I''m working on making a better xen faq. Hopefully I can use it to > > replace the one we now have on the wiki. > > Please, don''t start a new one, but improve the one that is there! > > > > > I''d love to know what people think really are the most frequently > > asked questions? > > Hard to say ad-hoc. I think your start looking at the archives is a good > one. > > Add these you think which are not covered in the FAQ, and remove these > which are not up to date anymore. (Answers which are still valid but > don''t seem frequently asked anymore should stay - they might just not be > frequently asked on the list because they are on the FAQ and some people > read it. > > Apart from that, a lot problems I see occuring and reoccuring with Xen, > and coming as questions to the list are either: > > - very strange behaviour of Xen under very special circumstances, like > specific (broken) hardware, and very specific setups, together with > quite esoteric and hard to debug errors occuring. > There are so many versions of Xen out there, and every distribution has > their own specific set of patches to Xen and the Xen Linux Kernel(and > thesde all are combined with gazillions of different hardware setups), > that it''s hard to catch all these problems. > > - bad error reporting and logging. This is not a documentation problem. > I did not run into these problems for a while because I have my fixed > setup, but there was times when I found it really bad how errors are > reported in Xen: > - very first, the logfile where you _might_ find some useful > information in ist the one with "debug" in it''s name - which is opposite > to usual behaviour. Normally, in debug i''d expect strange stuff only > developers understand, and in the normal log, stuff useful for users is > saved. Xen is the other way around. > - bad error checking and reporting in the userspace tools. Like, for > example, if you don''t set qemu_dm right in the config file, instead of > getting a decent warning, one just gets a Qemu screen which stays blank. > There was some other common misconfiguration that occured sometimes, and > resulted in a totally esoteric error message - I forgot it sadly. There > might be more of them. > > - people who don''t read the FAQ, user manual(admittedly outdated and > missing a lot of important things, still gives a very good overview of > what xen is about), and fail to search mailing lists. Sadly, you won''t > catch these with a FAQ, and my attempts to set up a list netiquette > where not recognized by XenSource. even if one employee of them told me > he wanted to get the netiquette onto the List subscription page. > > > my 2 cents. > Henning > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Artur Linhart - Linux communication
2007-Jul-13 07:59 UTC
[Xen-devel] RE: [Xen-users] Quest for a better FAQ
Hello, After I got gray hairs and already wrote a hearthbreaking e-mail to this conference why the hell my hvm domain will not start I figured out I do not have installed the package libsdl-console, which is necessary for the start even if I specified sdl=0 in the domain configuration file. I think, this package should be listed in the required packages for xen (at least version 3.1.0), but I haven''t seen it in some xen documentation or howto. So, maybe into the faq could come a hint about the recommended / required libraries even if running DomU with vnc access only - something like "What libraries should I have installed if I want to be sure I can start xen HVM domain" or something like that :-). From my research, I have installed following packages, which have not been installed by default (using Debian Etch 4.0), so, maybe this could be added to the faq you are creating just now (the libraries installed by default are very dependent on the distribution which is used). So, I installed following packages which have not been installed by default in Debian Etch 4.0: bridge-utils screen python python-twisted python-xml (this package is normally also not listed in the documentation as required) libsdl-console (second library not listed in the available documentations) iproute libcurl3-dev There is already isntalled the library libssl0.9.8, but I had to create the link to libssl0.9.7 by the statement ln -s /usr/lib/libcrypto.so.0.9.8 /usr/lib/libcrypto.so.0.9.7 because xen needed from me the version 0.9.7 According the the usage of the local sdl library - if on the server are installed o x-windows, this was a problem for me and I could not get framebuffer working at all... So maybe also another libraries are necessary if I want to attach to the DomU with graphic output locally... With best regards, Artur -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Dylan Martin Sent: Tuesday, July 10, 2007 2:40 AM To: Xen Users Subject: [Xen-users] Quest for a better FAQ I''m working on making a better xen faq. Hopefully I can use it to replace the one we now have on the wiki. I''d love to know what people think really are the most frequently asked questions? I''m going to paw through the mountains of data that is the xen-users archive and see what I see. That should be interesting, but probably not as useful as your opinions. -Dylan _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users __________ Informace od NOD32 2388 (20070710) __________ Tato zprava byla proverena antivirovym systemem NOD32. http://www.nod32.cz _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel