Difference between revisions of "Xen Document Days/TODO"

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=== Big work items ===
 
=== Big work items ===
  
* Review and update http://en.wikipedia.org/wiki/Xen - in particular the "Host: Unix-like systems" is out-of-date.
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* Review and update http://en.wikipedia.org/wiki/Xen - in particular the "Host: Unix-like systems" is out-of-date. The Guest section is too.
  
 
* Given that we are getting a lot more total novices to the community I was wondering whether it makes sense to add something like: getting started with xen-tools. See http://www.virtuatopia.com/index.php/Building_a_Xen_Guest_Domain_using_Xen-Tools and http://xen-tools.org/software/xen-tools/ and http://www.gossamer-threads.com/lists/xen/users/246910 this. Interesting quote:  
 
* Given that we are getting a lot more total novices to the community I was wondering whether it makes sense to add something like: getting started with xen-tools. See http://www.virtuatopia.com/index.php/Building_a_Xen_Guest_Domain_using_Xen-Tools and http://xen-tools.org/software/xen-tools/ and http://www.gossamer-threads.com/lists/xen/users/246910 this. Interesting quote:  

Revision as of 17:59, 12 June 2012

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Requested Documentation

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Big work items

Pretty similar to the setup I use all the time on my own. "Just works",
once you get around some issues, particularly the network setup.
1. Do not dedicate physical partitions to each VMs. It's too unflexible,
almost nobody uses it so (unless they really know what they are doing),
you will not find much references about issues specific to that setup.
The most simple way is to store VM's disks as files. A better one, but
little bit more complex, to use LVM volumes. If you are already familiar
with LVM you probably want to go straight for LVM.
2. Set up your network manually, not via xend's network scripts. Do not
attempt to export raw ethX to your VM's. Instead, set up a ethernet
bridge on each ethX you wish to use, which is a regular way. Then, in
the config file of each VM, you may specify to which bridge it should be
plugged.
http://wiki.xen.org/wiki/XenNetworking
3. Use xen-tools to perform the initial install of the VM's, it does
good job taking care of lots of small details. The default config file
is heavily commented.
http://www.virtuatopia.com/index.php/Building_a_Xen_Guest_Domain_using_Xen-Tools
  • Distros and Users: we need to provide better information on Xen users and distros
  • Feature status docs for end-users showing which features are expected to work in 4.0 and, possibly 4.1.2. Most people don't know if Feature X is even supposed to work on the Xen build their distro uses. And almost everything is broken somewhere! This is tricky since 4.0 (debian) still has rough edges like immediate panic when doing mem-set on a HV domU by mistake
    • Lars.kurth One way to approach handle this is to go through release notes and old blog posts and collate a table.
  • An XCP Overview (similar to Xen Overview)
  • A Xen Security Guide: The different options in Xen for Security, trade-offs, how to set them up, how to test Xen for security and how to optimize for different scenarios
    • Lars.kurth 09:48, 27 March 2012 (UTC): Category:Security contains some security related docs
    • Lars.kurth 11:01, 4 April 2012 (UTC): It would be good if we could document a) XSM, b) Introspection API, c) Xen and SELinux in Dom0, d) Memory Access API (introduced in 4.1)
  • User Docs that where migrating content would make sense and update such as (we can attach PDF's to the wiki now for starters, or we can use a conversion tool

In progress:

  • An Overview over Xen for people who do not yet use Xen, to help them make a decision on whether Xen is for them (aka "Why Xen" and "Which Xen") (be sure to mention "fastest" ;)
    • Lars.kurth 09:48, 27 March 2012 (UTC): am working on this and am almost ready to publish on the wiki

Done recently:

  • A Xen Overview which explains the top level architectural features and options, trade-offs and links to examples tutorials that show how you set these up
  • A Xen Tuning Guide: different options in Xen impacting performance, how to set them up, how to tune
  • List i.e. stuff what to test after packaging. This would avoid the current state of affairs where most distros are infact broken w/re to Xen. See Distros

Categories

Admin docs

  • Setting boot order for domUs (PV and HVM)
  • Chaining pypxeboot and pygrub

[[User:Fheigl|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. 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.


  • xenpm usage recommendations
  • setting up vnc mime magic for xen in firefox (oracle has srpms for a vnc client plugin)
  • vcpu pinning
  • using xm trigger to poweroff or firing off NMIs
  • Expand Host Configuration/Networking docs to cover non-bridge network configurations supported by xend (e.g. routed, nat'd). Possibly split into a page per config.

Developer Docs

Docs that need attention or are missing

  • Make XAPI docs (built from source) available on xen.org
  • PVOPS portal on xen.org - Konrad volunteered
  • some more xenstore docs (i.e. recent python bindings that were sent to the -users list
  • Using libxenstat python bindings (imo they're broken)
  • More PV protocol docs (see recent patches to blkif.h for example)
  • Document xenstore paths used by guests and toolstack etc
  • Xen command line options documentation in tree (started, but not complete)

Wiki Maintenance

Fix artcles that need attention

Review Categorization

We need to go through some of the categies on the http://wiki.xen.org/wiki/Main_Page and decise whether there are documents in each category that need to be highlighted in a trail, etc.

Loose ends on migration