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This section contains the discussion happening on the | This section contains the discussion happening on the | ||
[http://www.redhat.com/mailman/listinfo/fedora-virt fedora-virt list]. | [http://www.redhat.com/mailman/listinfo/fedora-virt fedora-virt list]. | ||
==== Fedora Virt Status ==== | |||
[[MarkMcLoughlin|Mark McLoughlin]] | |||
posted<ref>http://www.redhat.com/archives/fedora-virt/2009-October/msg00138.html</ref> | |||
another excellent round up of virt related bugs and developments. Mark reports | |||
"Thankfully, the virt blocker list is now clear, but if you're looking | |||
to help with making Fedora 12 even better, there's no better place to | |||
start than the F12 target tracker bug<ref>https://bugzilla.redhat.com/showdependencytree.cgi?id=F12VirtTarget&hide_resolved=1</ref>: | |||
There's over 100 bugs there that need your help!" | |||
<references /> | |||
==== Help testing the Windows Registry feature of libguestfs ==== | |||
[[RichardJones|Richard Jones]] | |||
asked<ref>http://www.redhat.com/archives/fedora-virt/2009-October/msg00128.html</ref> for some help testing a new feature of {{package|libguestfs}} | |||
"If you have any Windows guests, then you can help Fedora to support | |||
Windows guests better by spending a few minutes testing the Windows | |||
Registry feature we just added to libguestfs 1.0.75." | |||
To help, all you need is: | |||
* A Windows NT/200x/XP/Vista/7/... guest | |||
* Fedora 12 or Fedora Rawhide host | |||
* <code>libguestfs-tools</code> >= 1.0.75 (from updates or koji<ref>http://koji.fedoraproject.org/koji/packageinfo?packageID=8391</ref>) | |||
* a few minutes of your time | |||
<references /> | |||
==== KSM Tuning in Fedora 12 ==== | ==== KSM Tuning in Fedora 12 ==== |
Revision as of 04:44, 2 November 2009
Virtualization
In this section, we cover discussion of Fedora virtualization technologies on the @fedora-virt and @libvirt-list lists.
Contributing Writer: Dale Bewley
Fedora Virtualization List
This section contains the discussion happening on the fedora-virt list.
Fedora Virt Status
Mark McLoughlin posted[1] another excellent round up of virt related bugs and developments. Mark reports "Thankfully, the virt blocker list is now clear, but if you're looking to help with making Fedora 12 even better, there's no better place to start than the F12 target tracker bug[2]:
There's over 100 bugs there that need your help!"
Help testing the Windows Registry feature of libguestfs
Richard Jones
asked[1] for some help testing a new feature of libguestfs
"If you have any Windows guests, then you can help Fedora to support Windows guests better by spending a few minutes testing the Windows Registry feature we just added to libguestfs 1.0.75."
To help, all you need is:
- A Windows NT/200x/XP/Vista/7/... guest
- Fedora 12 or Fedora Rawhide host
libguestfs-tools
>= 1.0.75 (from updates or koji[2])- a few minutes of your time
KSM Tuning in Fedora 12
Mark McLoughlin
described[1]
the default state of KSM[2] on Fedora systems.
"For Fedora 13, it'll be off by default in the kernel and the recommended
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 changes max pages and the only way of disabling it is by manually
writing zero to /sys/kernel/mm/ksm/run
."
At release of Fedora 12 the kernel will default to a maximum of 2000 merged memory pages. A future F12 kernel update to 2.6.32 will likely disable KSM by default.
To take advantage of KSM in Fedora 12, the ksm
service must be enabled:
sudo chkconfig ksm on
Mark McLoughlin
also noted[3]
The maximum number of pages which may be merged defaults to half of the system
memory, and may also be manually defined in /etc/sysconfig/ksm
.
"Here's the logic we have in the init script[4]:"
# 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] }
Justin Forbes points out[5] "The limit to half of total memory is because ksm pages are unswappable at this time. To be fixed in a future kernel."
A second service, ksmtuned
, may also be enabled.
Ksmtuned regulates how aggressively the system will attempt to merge pages.
Parameters such as how many pages to scan before sleeping and how long to
sleep may be configured in /etc/ksmtuned.conf
.
Memory pages must be flagged as mergable before KSM will scan them looking for
duplicates. At present only Qemu pages will be marked as such.
As described in the kernel docs[6],
the effect of KSM system memory may be examined in /sys/kernel/mm/ksm
.
"A high ratio of pages_sharing to pages_shared indicates good sharing, but
a high ratio of pages_unshared to pages_sharing indicates wasted effort."
- ↑ http://www.redhat.com/archives/fedora-virt/2009-October/msg00119.html
- ↑ http://fedoraproject.org/wiki/Features/KSM
- ↑ http://www.redhat.com/archives/fedora-virt/2009-October/msg00112.html
- ↑ http://gitorious.org/ksm-control-scripts/ksm-control-scripts
- ↑ http://www.redhat.com/archives/fedora-virt/2009-October/msg00115.html
- ↑ http://www.kernel.org/doc/Documentation/vm/ksm.txt
Libvirt List
This section contains the discussion happening on the libvir-list.
Rewrite the QEMU monitor handling
Daniel Berrange posted[1] a "patch series [which] rewrites the QEMU monitor handling almost completely.
The key theme here is to move from a totally synchronous way of
interacting with the monitor, to a totally asynchronous way. This
allows "
" to handle receipt & dispatch of asychronous events from
QEMU. For example a notification of a disk-full error, or VM state
change. In the process of doing this re-factoring I have also
dropped in basic support/infrastructure for the JSON based monitor."
libvirt
Node device enumeration with udev
Dave Allan posted[1] "a fully functional version of the node device udev[2] based backend, incorporating all the feedback from earlier revisions." "...I have also included a patch removing the DevKit backend."
Also see FWN#146 [3] for some coverage of the host device enumeration API.