Xen Document Days/TODO

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Go back to Xen Project Document Days

Requested Documentation

Feel free to comment on items using the following convention: * {{Comment|~~~~:}} your comment Feel free to add new workitems using the following convention: ==== Workitem ==== ~~~~: work-item description

Performance-related Documentation

The documentation on Performance Tuning seems thin, given the importance of the subject:

• Category:Performance Lists the Performance docs currently available. It seems rather sparse.
• Network_Throughput_and_Performance_Guide Has lots of interesting information, but it is oriented for XenServer/XCP. This needs to be recast as a true Xen Project document.
• Tuning_Xen_for_Performance Is potentially the most important document, but it has only a few topics and not that many details. There is some discussion about this page in section 3.12

Integration Documentation

These documents are for projects which users need to use in conjunction with Xen Project. The goal of these documents is not to repeat the documentation found in other projects, but to give people the essential information required to integrate them into their Xen Project installation.

Most of these documents are still quite new and can benefit from improvements by people who have used these projects.

• Using Ceph storage
• Using Gluster storage
• Cloud Operating Systems (e.g., Mirage OS, LING, HaLVM, OSv, etc.) and how they relate to Xen Project

Missing bits in Beginners Guide

Xen_Project_Beginners_Guide has a few TODOs in it. In particular, it is missing some diagrams

(IMPORTANT) Linux Distros

It seems that the list of Linux Distros which support Xen is a lot larger than listed on this wiki.

• Funtoo
• Mageia
• Univention Corporate Server (UCS)
• Are there others?

In progress (some just need double checking whether finished)

• FreeBSD_Dom0

Draft a list of Questions for a User Survey

• Lars.kurth 10:09, 30 April 2014 (UTC) : See Xen Project User Survey

Easy tasks for Beginners

You may want to read Wiki Help if you do not have an account.

Migrate useful blog posts to wiki

Sift through blog.xenproject.org and copy useful posts to wiki. This will mainly be a reformatting exercise. Before you copy an article, perform a search on the wiki (headline or key word) to see whether the post exists already. If in doubt, ask on the IRC channel.

Fix articles that need attention

• Category:Contains_Needs_Formatting - Pages that need formatting
• Category:Contains_Needs_Action - Pages that need fixing. Go through these, and if you get stuck ask people on the IRC channel for help, or go to the next page.
• Category:Contains_TODO - Pages that have a TODO item on the page. Go through these, and if you get stuck ask people on the IRC channel for help, or go to the next page.

Review Categorization

• Sometimes new pages on the wiki are not created with categories. You can find these by going to Special:UncategorizedPages. Documentation about which category is used where can be found in Categories for Authors. If in doubt ask on IRC.

Pages With Comments or Improvement Suggestions

• We ask users to highlight issues using talk pages, following the conventions outlined in Help:Talk Pages. Comments made using these conventions can be identified using the Category:Pages with comments.

Links to Developer Documents on XenBits

• There are a number of developer-related documents which are hosted on XenBits which should be locatable through this Wiki. Ideally, someone should work backwards from the XenBits document index to make sure each document exists in a link from the appropriate Wiki page.

If no appropriate Wiki page exists, one should be created or listed here for creation. For function-specific docs which don't necessarily deserve a Wiki page, we should have a catch-all page to let people know that these docs exist.

Missing Pages

• Special:WantedPages - You can find missing pages by going to this link. There are several courses of actoin that can be taken:
  • The page is needed : Add {{TODO|With a comment}} to the top of the page
  • The page is not needed : Remove the reference to the page (follow the link in the bracket besides the page)
  • Note that the list of Wanted pages contains lots of needed translations and categories, which you can ignore
  • If in doubt, ask for help on the IRC channel

 Double-p 09:55, 25 February 2013 (UTC): There are a gazillion Template-Whatever including a TODO, really needed?  Lars.kurth 17:40, 25 March 2013 (UTC): See #Special:WantedPages_broken

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Xen : Open work items

UEFI Secure Boot

Write a document on how to sign the xen binary for UEFI Secure Boot. Potential reference here: Dealing With Secure Boot

Mirage OS

While much documentation is available at their website, we need to have pages here which describe Mirage OS and give useful pointers to their docs.

Ideally, it would be good to have extensive documentation for this project on this Wiki, as Mirage OS is being fostered by Xen Project.

Documentation on lib(xen)vchan

The header has some stuff, but a more complete guide would be useful.

The usage of the example code is also not documented. http://lists.xen.org/archives/html/xen-users/2014-01/msg00162.html has some (incomplete) info.

Describe the different ways, and necessary components, to create PVs using xl

Raised by mail by Matthias Blankenhaus (who is prepared to take the lead, but needs help): This document would describe the different ways, and necessary components that each way requires, to create PVs using xl. Right now there are at least the following cases:

• loopbacked vhds
  • single partition format
  • disk format
• qemu backed vhds
  • qcow / qcow2
• LVS backed image

This is not a complete list. Also the mileage of each case differs depending on the kernel features enabled in dom0/domu and also depending on the Xen version. Furthermore, certain format require additional infrastructure like the tap device.

All in all, this a complex topic that needs clarification. Doing this based on the lowest common denominator, xl, would clarify many things. In addition, baseline performance data on all of the above would help a great deal. Matthias volunteered to run the majority of needed perf tests

Review and Update: xenpm usage recommendations

There is Xen power management and Xenpm command which may all be outdated. These should probably be reviewed and updated.

HOWTO : using xl trigger to poweroff or firing off NMIs

Howto on using xl trigger to poweroff or firing off NMIs.

HOWTO: Chain pypxeboot and pygrub

How to chain pypxeboot and pygrub

•  Lars.kurth 10:35, 27 March 2012 (UTC): Is pypxeboot popular at all?
•  Fheigl: I added that. It is somewhat common, OVM 2 and OVM 3 rely on it for PXE installs. I'm not sure if xenpvnetboot is the same, or works. The use case is "you want to use the same installation server for Xen VMs and phys. servers. You want to be able to reinstall them based on PXE reply.
•  Fheigl: There is documentation for pypxeboot, but there is no (afaik) documentation for how pygrub is used as a fallback loader. We wasted many days just to get some hack that can't even load a newer kernel. Which sucks, in the end you spend more time/money making PV PXE boot work than you save by using virtualized servers.
•  Fheigl: How could it be popular given the state of documentation. <= Key issue to the left of this sentence.
•  Lars.kurth 16:03, 19 September 2012 (UTC): wondering whether this video contains what is needed
•  Ijc 11:01, 25 June 2014 (UTC): Although I've not watched the whole thing I stepped through that video enough to see all the slides (I think) and I didn't see anything about this topic or anything like it.
•  Ijc 11:17, 25 June 2014 (UTC): I've downloaded pypxeboot 0.0.3 and as far as I can tell the fallback to pygrub is supposed to happen automatically if pxelinyx.cfg says to do a local boot. If this doesn't Just Work then I think that is a code bug rather than a documentation issue. I'd recommend retiring this docs TODO in favour of a bug report to the pypxeboot authors and/or xen-devel. I googled around a bit and didn't find any existing bug reports anywhere.

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Visually distinguish Xen, MirageOS and Community Documentation better

 Lars.kurth 15:32, 28 January 2013 (UTC): Users are getting confused when looking at wiki pages. If there was a visual way to distinguish Xen, MirageOS and Other content better, this would help. We could use colors and skinning when it comes to various elements, as well as mascots/logos:

• For example: Help:Contents has a different feel (and colour scheme)
• This could be replicated in trail boxes and other elements
• We can also use mascots

But first, I need to investigate what is possible.

 Lars.kurth 16:14, 28 January 2013 (UTC): Looks as if the only way this can be done is via Custom Namespaces. The only way to do this properly is to

• Have different namespaces for Xen, MirageOS, ... and Community stuff and keep all the common stuff in Xen
• The name spaces could then be styled differently, for example the Help namespace includes the ns-12 style into the body attributes, whereas the Main (default) namespace uses the ns-14 style.
• Custom namespaces can be created by changing the config and are linked to custom styles
• The styles are then defined in MediaWiki:Common.css

Implications of using custom namespaces:

• Search: Pages in a custom namespace do not show up in default search results. So if we had a custom MirageOS namespace, it would mean that search results for MirageOS would not show up. One would need to go to Advanced Search and select MirageOS
• Rename: Renaming pages is possible and as straightforward as renaming pages
• Xen Namespace: The Xen namespace exists already, this may need to be renamed
• Categories and Namespaces: Categories cross namespaces. In other words, Category:XXX would go across all namespaces. As an example, see Category:Wiki_Management

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Mediwiki Issues

Special:WantedPages broken

Issue 1: Pages that need translation are spamming the list

• Solution: fix language templates and mark with {{Stub translation}}
•  Lars.kurth 16:48, 28 January 2013 (UTC): There is something wrong with the language templates, essentially spamming the wanted pages. Do ignore these instructions until fixed.
•  Lars.kurth 23:28, 11 February 2013 (UTC): Fixed language template issues by removing most languages from the templates
•  Lars.kurth 18:03, 25 March 2013 (UTC): Started marking pages with {{Stub translation}}

Issue 2: Missing templates are spamming the list

• Solution: mark missing templates with {{Undefined Template}}
•  Lars.kurth 17:27, 25 March 2013 (UTC): Started marking all missing templates with {{Undefined Template}}

Issue 3: Missing categories are spamming the list

• Solution: mark with {{Stub category}}
•  Lars.kurth 18:03, 25 March 2013 (UTC): Started marking pages with {{Stub category}}

Categories & Indexes

•  Lars.kurth 13:54, 29 January 2013 (UTC): Combined categories such as list all XCP FAQs have been asked for sevceral times
• Investigate plug-ins

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Developer Docs

Docs that need attention or are missing

• Make XAPI docs (built from source) available on XenProject.org
• some more xenstore docs (i.e. recent python bindings that were sent to the -users list)
  •  Ijc 12:13, 25 June 2014 (UTC): I don't think these are included in Xen? Need a reference.
• Using libxenstat python bindings (imo they're broken)
  •  Ijc 12:13, 25 June 2014 (UTC): Is this a bug report? If they are broken we should fix them (as well as potentially documenting them)
• More PV protocol docs (see recent patches to blkif.h for example)
  •  Ijc 12:13, 25 June 2014 (UTC): blkif.h and netif.h are perhaps the most critical ones and those are now pretty good. But the rest (fbif.h, kbdif.h, pciif.h, usbif.h, tmpif.h and vscsiif.h) could all stand to be improved.
• Document xenstore paths used by guests and toolstack etc
  •  Ijc 16:10, 26 November 2012 (UTC): This is now in tree: http://xenbits.xen.org/docs/unstable/misc/xenstore-paths.html

Done Recently

Xen 4.3 / 4.4 Documentation : Spice Config Example for upstream QEMU

Take this thread and convert into an Example

 Lars.kurth 16:56, 9 April 2014 (UTC) Created SPICE_support_in_Xen for now