virtual infrastructure: kvm, uvb + libvirt bryan mclellan [email protected] senior systems...
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Virtual Infrastructure:kvm, uvb + libvirt
Bryan McLellanhttp://loftninjas.org [email protected]
Senior Systems AdministratorWidemile
Widemile is awesome
I work there, and thus the world is a better place for all of humanity.
What I got for “free”
•Identical Blades
•Running non identical Debian installs (etch/sid, i386/amd64)
•Running different versions of vmware-server
• OS, software, installed by hand
• Configure using notes in an outlook public folder
•Host database tracked with DNS
vm04-something.test.widemile.com
Problems
• Lack of Homogeneity
• Monkey configuration sucks
• Documentation offensive
http://www.flickr.com/photos/annebuzz/2666654754/
What I did
• Lack of Homogeneity– debian pxe install with preseeds
• Monkey configuration sucks– puppify (configuration management)– capistrano (ruby scripting over ssh)– iclassify (node classification)
• Documentation offensive– Configuration management is self documenting– Wikify the notes
http://www.flickr.com/photos/jpasden/67513019/
We can always do better
What upset me (nobody else cares)
• PXE installs take soooooo long• Backporting too many packages to debian• Interacting with VMware programmatically
too much work.• VMware UIs cost $$• Dreams: cpu/ram hotplug, live migration
How I Learned to Stop Worrying and Love the Bomb
• PXE installs take soooooo long– deb-bootstrap with ubuntu-vm-builder (2.5min)
• Backporting too many packages to debian– switch to Ubuntu!
• Interacting with VMware programmatically too much work.– libvirt is much easier and cleaner
• VMware UIs cost $$– Libvirt is free
• Dreams: cpu/ram hotplug, live migration– Word on the street is that kvm + libvirt support these– I don’t think they’re there yet though.
libvirt – virtualization API
Started at Redhat ‘s Emerging Technology GroupWas Xen focused, but Redhat recently bought Qumranet, makers of KVMUbuntu/Canonical picked KVM as virtualization platform of choicelibvirt doesn’t really support all thatProvides CLI management (virsh)Provides GUI management (virt-manager)
virsh
virt-manager
ubuntu-vm-builderBash script wrapper for deb-bootstrap + qemuapt-get install ubuntu-vm-builder
capistrano script:vmware: 102 linesuvb: 12 lines
ubuntu-vm-builder kvm hardy --addpkg openssh-server -d /srv/kvm/#{hostname} --domain #{domain} --hostname #{hostname} --mem #{memory} --mirror http://ubuntu.widemile.com/ubuntu--libvirt qemu:///system--bridge #{eth0}
ubuntu-vm-builderBash script wrapper for deb-bootstrap + qemuapt-get install ubuntu-vm-builder
capistrano script:vmware: 102 linesuvb: 12 lines
ubuntu-vm-builder kvm hardy --addpkg openssh-server -d /srv/kvm/#{hostname} --domain #{domain} --hostname #{hostname} --mem #{memory} --mirror http://ubuntu.widemile.com/ubuntu--libvirt qemu:///system--bridge #{eth0}
Not a lot of enterprise features yetBridging vs NAT
Root password / creates user
kvm• The cool hypervisor on the block (ubuntu, redhat)• Kernel modifications are mainlined (unlike xen)• Super fast / lightweight (feel the wind in your hair)• Growing fast
class kvm { case $lsbdistid { "Ubuntu": { # Only Ubuntu releases are new enough for this
package { "kvm": ensure => present; "libvirt-bin": ensure => present; "ubuntu-vm-builder": ensure => latest; }
file { "/srv/kvm": ensure => directory, group => admins, mode => 0775, }
# Permissions required for remote access # Puppet doesn't support managing the libvirtd group members through
the group type file { "/var/run/libvirt/libvirt-sock": group => admins, require => Service["libvirt-bin"]; "/var/run/libvirt/libvirt-sock-ro": group => admins, require => Service["libvirt-bin"]; }
service { "libvirt-bin": ensure => running, hasstatus => true, require => Package["libvirt-bin"], }
# required by u-v-b exec { "devmapper-autoload": command => "/bin/echo dm_mod >> /etc/modules", onlyif => "/usr/bin/test `grep -c '^dm_mod' /etc/modules` -lt 1", } exec { "devmapper-load": command => "/sbin/modprobe dm_mod", onlyif => "/usr/bin/test `/bin/lsmod | grep -c '^dm_mod'` -lt 1", } realize Group["libvirtd"] } }}
http://loftninjas.org