FWN/Beats/Virtualization

From FedoraProject

< FWN | Beats(Difference between revisions)
Jump to: navigation, search
(Fedora Virtualization List: begin next fwn)
(Fedora Virtualization List)
 
(32 intermediate revisions by 2 users not shown)
Line 1: Line 1:
 
[[Category:Virtualization]] <!-- do not copy into FWN issue -->
 
[[Category:Virtualization]] <!-- do not copy into FWN issue -->
 
  
 
{{Anchor|Virtualization}}
 
{{Anchor|Virtualization}}
 +
  
 
== Virtualization ==
 
== Virtualization ==
 
In this section, we cover discussion of Fedora virtualization technologies on the
 
In this section, we cover discussion of Fedora virtualization technologies on the
@fedora-virt and @virt-tools lists..
+
@fedora-virt list.
  
 
Contributing Writer: [[User:Dale | Dale Bewley]]
 
Contributing Writer: [[User:Dale | Dale Bewley]]
Line 14: Line 14:
 
[http://www.redhat.com/mailman/listinfo/fedora-virt fedora-virt list].
 
[http://www.redhat.com/mailman/listinfo/fedora-virt fedora-virt list].
  
==== KSM Tuning ====
+
==== Virt Status Report ====
[[IzikEidus|Izik Eidus]]
+
<ref>http://www.redhat.com/archives/fedora-virt/2009-October/msg00110.html</ref>
+
 
+
" by default enabled and only with 2000 kernel pages... What I am worried about is that users wont use the ksm tunning script and would just run ksm with this 2000 kernel pages - the result would be that ksm will probably merge just the zero pages (that could be alot of memory) and the user might not know
+
 
+
that much more memory can be saved...
+
 
+
 
+
Is it possible to at least make ksm disabled by default? so the users will have to run the ksm tunning script when they want to start ksm?
+
 
+
And if we set it to disabled by default, cant we set the initialized values
+
into more realistic value? (like 1/4 of the memory in the mainline kernels? )
+
"
+
 
+
[[MarkMcLoughlin|Mark McLoughlin]]
+
<ref>http://www.redhat.com/archives/fedora-virt/2009-October/msg00112.html</ref>
+
 
+
"ksm is disabled by default currently"
+
 
+
"Here's the logic we have in the init script<ref>http://gitorious.org/ksm-control-scripts/ksm-control-scripts</ref>:
+
 
+
<pre>
+
  # unless KSM_MAX_KERNEL_PAGES is set, let ksm munch up to half of total memory.
+
  default_max_kernel_pages () {
+
      local total pagesize
+
      total=`awk '/^MemTotal:/ {print $2}' /proc/meminfo`
+
      pagesize=`getconf PAGESIZE`
+
      echo $[total * 1024 / pagesize / 2]
+
  }
+
</pre>
+
 
+
 
[[JustinForbes|Justin Forbes]]
 
[[JustinForbes|Justin Forbes]]
<ref>http://www.redhat.com/archives/fedora-virt/2009-October/msg00115.html</ref>
+
posted<ref>http://www.redhat.com/archives/fedora-virt/2009-December/msg00056.html</ref> a Fedora virtualization status report.
 +
Justin pointed out F13 bugs<ref>http://fedoraproject.org/wiki/Virtualization_bugs</ref> now include Important and Pony classifications in addition to Blocker and Target.
  
"There are actually 2 init scripts.  One to turn on ksm, and one for tuning.
+
<references />
The actual ksm init script simply makes sure ksm is turned on in the kernel
+
and sets max_kernel_pages to half of system memory.  The ksmtuned script is
+
a bit more involved."
+
  
[[MarkMcLoughlin|Mark McLoughlin]]
+
==== RHEL and Fedora Virtualization Feature Parity ====
<ref>http://www.redhat.com/archives/fedora-virt/2009-October/msg00119.html</ref>
+
Robert Day wondered how the virtualization features<ref>http://www.redhat.com/virtualization/rhev/</ref> of Red Hat Enterprise Linux 5.4
"For Fedora 13, it'll be off by default in the kernel and the recommended
+
compared to Fedora 12.
way of switching it on is with 'chkconfig ksm on'
+
  
For Fedora 12, it's on by default in the kernel, 'chkconfig ksm on' just
+
[[DanielBerrange|Daniel Berrange]]
changes max pages and the only way of disabling it is by manually
+
explained<ref>http://www.redhat.com/archives/fedora-virt/2009-December/msg00040.html</ref>
writing zero to {{filename|/sys/kernel/mm/ksm/run}}"
+
"The KVM based virtualization in RHEL-5.4 is not nearly so far behind
 
+
Fedora as you might think. The {{package|libvirt}} mgmt stack in RHEL-5.4 was
"We'll probably end up with this behaviour in F12 updates at some point
+
rebased to be near parity with [[Releases/11|Fedora 11]], and KVM in RHEL-5.4 is
anyway when 2.6.32 is pulled in"
+
also pretty close to that using what's best described as a hybrid of
 
+
kvm-83 and kvm-84."
[[JustinForbes|Justin Forbes]]
+
"The limit to half of total memory is because ksm pages are unswappable at
+
this time.  To be fixed in a future kernel."
+
  
 
<references />
 
<references />
  
=== Virtualization Tools List ===
 
This section contains the discussion happening on the
 
[http://www.redhat.com/mailman/listinfo/virt-tools-list virt-tools-list list].
 
 
==== libosinfo Revisited ====
 
[[ArjunRoy|Arjun Roy]]
 
revived<ref>http://www.redhat.com/archives/virt-tools-list/2009-October/msg00091.html</ref>
 
discussion of a library to track details of OS distributions for use by tools
 
such as {{package|python-virtinst}} and <code>virt-inspector</code>. LibOSinfo was first proposed<ref>http://fedoraproject.org/wiki/FWN/Issue180#libosinfo:_Library_for_Virt_OS.2Fdistro_Metadata</ref>
 
by [[ColeRobinson|Cole Robinson]].
 
  
 +
====  ====
 
<references />
 
<references />
  
=== Other Sources ===
+
==== ====
 
+
==== Using Kernel Samepage Merging with KVM ====
+
An upcoming feature  of [[Releases/12|Fedora 12]] is
+
KSM<ref>http://fedoraproject.org/wiki/Features/KSM</ref>.
+
"Kernel SamePage Merging is a recent linux kernel feature which combines
+
identical memory pages from multiple processes into one copy on write memory
+
region."
+
[[HaydnSolomon|Haydn Solomon]] described<ref>http://www.linux-kvm.com/content/using-ksm-kernel-samepage-merging-kvm</ref> how KSM and KVM work together.
+
 
+
 
<references />
 
<references />

Latest revision as of 18:09, 18 December 2009



Contents

[edit] Virtualization

In this section, we cover discussion of Fedora virtualization technologies on the @fedora-virt list.

Contributing Writer: Dale Bewley

[edit] Fedora Virtualization List

This section contains the discussion happening on the fedora-virt list.

[edit] Virt Status Report

Justin Forbes posted[1] a Fedora virtualization status report. Justin pointed out F13 bugs[2] now include Important and Pony classifications in addition to Blocker and Target.

  1. http://www.redhat.com/archives/fedora-virt/2009-December/msg00056.html
  2. http://fedoraproject.org/wiki/Virtualization_bugs

[edit] RHEL and Fedora Virtualization Feature Parity

Robert Day wondered how the virtualization features[1] of Red Hat Enterprise Linux 5.4 compared to Fedora 12.

Daniel Berrange explained[2] "The KVM based virtualization in RHEL-5.4 is not nearly so far behind Fedora as you might think. The Package-x-generic-16.pnglibvirt mgmt stack in RHEL-5.4 was rebased to be near parity with Fedora 11, and KVM in RHEL-5.4 is also pretty close to that using what's best described as a hybrid of kvm-83 and kvm-84."

  1. http://www.redhat.com/virtualization/rhev/
  2. http://www.redhat.com/archives/fedora-virt/2009-December/msg00040.html


[edit]


[edit]