From Fedora Project Wiki
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==== remote management ==== | ==== remote management ==== | ||
==== Access guest files ==== | |||
; virt-cat: virt-cat Guest /var/log/messages # or /var/log/dmesg etc | |||
; guestfish: guestfish --ro -i -d Guest | |||
** ><fs> less /var/log/messages | |||
** guestfish -i -d Guest | |||
; virt-edit: virt-edit Guest /boot/grub/grub.conf | |||
><fs> emacs /boot/grub/grub.conf | |||
; virt-rescue: virt-rescue Guest | |||
><rescue> mount /dev/vg_foo/lv_root /sysroot | |||
><rescue> mount /dev/vda1 /sysroot/boot | |||
><rescue> vi /sysroot/boot/grub/grub.conf | |||
== Creating DomUs == | == Creating DomUs == | ||
Revision as of 11:37, 1 December 2010
Virtualization short cuts for noobs
Introduction
Purpose
Scope
Acronyms, descriptions
References
- http://www.linux-kvm.org/page/Documents
- KVM documentation page.
- http://www.linuxfoundation.org/collaborate/workgroups/networking/bridge
- description of the linux bridge implementation.
- http://en.gentoo-wiki.com/wiki/Bridging_Network_Interfaces
- http://en.gentoo-wiki.com/wiki/KVM#Networking_2
- Shows direct and indirect bridging.
- http://blog.loftninjas.org/2008/08/18/using-attach-interface-with-libvirt-and-qemukvm-on-ubuntu/
- about attach-interface.
- http://tjworld.net/wiki/Linux/Ubuntu/VirtualMachinesWithVDENetworking
- Virtual Machines With VDE Networking
- http://www.mythicalbeast.co.uk/linux/dnsmasq_howto.html
- HOWTO for dnsmasq
- http://www.tuxradar.com/content/howto-linux-and-windows-virtualization-kvm-and-qemu
- hands-on KVM usage and a bit of background information.
- http://www.ibm.com/developerworks/library/l-linuxvirt/index.html
- An overview of virtualization methods, architectures, and implementations. From 2006.
- Virtualization_Quick_Start
- Get going with KVM.
Open issues
- how to pin Dom0
- How do we pin Dom0 to a specific CPU?
Operating Environment
Which packages you need in order to run virtualization.
yum install @virtualization
or
- yum install libvirt
- yum install qemu-kvm
- yum install python-virtinst
- yum install virt-manager
- yum install virt-viewer
- yum install virt-top
Storage
- File based
- LVM Based
- NFS based
- iSCSI
Network
Network configuration needs.
- Bridging
- Direct
- NAT
- NAT/Route
Get direct bridging
Looks better: [Guest Configuration on Fedora 12 with Netcf] Source: [KVM w/o dnsmasq on CentOS 5.2 X64].
- cd /etc/sysconfig/network-scripts
- mkdir bak
- cp -p ifcfg-eth0 bak
- virsh iface-dumpxml eth0 > bak/eth0.xml
- cp bak/eth0.xml bak/kvmbr0.xml
- vi bak/kvmbr0.xml
- virsh iface-define bak/kvmbr0.xml
- virsh iface-list
- service network restart
- virsh edit fc13_1
- brctl show
The following didn't cut it, it simply prevented the DomU in starting, due to the missing 'default' network...
- virsh net-destroy default
- virsh net-autostart --disable default
- virsh net-autostart default
bak/kvmbr0.xml
<interface type='bridge' name='virbr0'>
<start mode="onboot"/>
<protocol family="ipv4">
<dhcp/>
</protocol>
<bridge stp="on">
<interface type="ethernet" name="eth0">
<mac address='d8:d3:85:e1:29:68'/>
</interface>
</bridge>
</interface>
virsh net-dumpxml default
<network>
<name>default</name>
<uuid>4eb269bb-b949-49ae-95b1-6e281b634c47</uuid>
<forward mode='route'/>
<bridge name='virbr0' stp='on' delay='0' />
<ip address='192.168.122.1' netmask='255.255.255.0'>
<dhcp>
<range start='192.168.122.2' end='192.168.122.254' />
</dhcp>
</ip>
</network>
Storage creation
LVM creation
- Create a partition of type 8e (Linux LVM)
- pvcreate /dev/sda5
- vgcreate LX /dev/sda5
- lvcreate --size 10G --name vol01 LX
Resource allocation
KVM
Xen
CPU
I/O
Number of devices
Administration
virsch
virsh help lists the supported commands.
See also [28. Managing guests with virsh]
Virsh operations commands of interest
- console
- get access to the console in the DomU.
- destroy
- as if you pulled the power cord, preferably use 'shutdown'.
- reboot
- reboot the domain.
- shutdown
- shutdown the domain.
- undefine
- remove all references to the domain. (Note; not sure if it is actually *all*).
- dumpxml
- list
- List the active domains. Use '--all' to include the the inactive containers to the list.
Virsh network commands of interest
- domifstat
- interface statistics.
- virsh domifstat z3 vif7.0
- attach-interface
- attach a network interface.
- virsh attach-interface z3 bridge eth1 --target eth1 --mac xx:xx:xx:xx:xx:xx
- net-edit
- For an description of the xml structure see: [XML format]
- net-list
- list networks.
virsh cpu commands of interest
- vcpuping <domain-id> <vcpuid> <cpulist>
- Pin a domains virtual cpu to a list of cpu's.
- virsh vcpupin z2 0 2
- virsh vcpuinfo z2
VCPU: 0 CPU: 2 State: idle CPU time: 9.8s CPU Affinity: --y-----
virt-install
virt-mananger
remote management
Access guest files
- virt-cat
- virt-cat Guest /var/log/messages # or /var/log/dmesg etc
- guestfish
- guestfish --ro -i -d Guest
- ><fs> less /var/log/messages
- guestfish -i -d Guest
- virt-edit
- virt-edit Guest /boot/grub/grub.conf
><fs> emacs /boot/grub/grub.conf
- virt-rescue
- virt-rescue Guest
><rescue> mount /dev/vg_foo/lv_root /sysroot ><rescue> mount /dev/vda1 /sysroot/boot ><rescue> vi /sysroot/boot/grub/grub.conf
Creating DomUs
Creating a CentOS 5.5 DomU
Xen: source:NFS, storage:LVM network:bridge;4
virt-install -p --name=z4 --ram=512 --vcpus=1 --disk path=/dev/loom/z4 --os-type=linux
--os-variant=rhel5 --location=nfs:192.168.42.132:/exports/isos/centos55 -x
"ks=nfs:192.168.42.132:/exports/ks/anaconda-ks.cfg ip=192.168.42.31 netmask=255.255.255.0
gateway=192.168.42.132 dns=192.168.42.32"
KVM: source:NFS, storage:LVM network:bridged-4
virt-install --connect=qemu:///system --name=z01 --ram=512 --vcpus=1 --disk path=/dev/LX/vol01 --os-type=linux --os-variant=rhel5 --network=bridge:virbr0 --network=bridge:virbr1 --network=bridge:virbr2 --network=bridge:virbr3 --location=nfs:192.168.42.132:/exports/isos/centos55 -x "ks=nfs:192.168.42.132:/exports/ks/kvm_centos55.cfg ip=192.168.42.31 netmask=255.255.255.0 gateway=192.168.42.132 dns=192.168.42.32"
Trouble shooting
virt-install
ERROR Host does not support virtualization type 'xen'
running on KVM, the '-p | --para-virt' is not supported.
error: Failed to get local hostname
- The hostname must be set.
- The system must be able to do a dns lookup of the hostname.
- e.g. put the hostname in /etc/hosts
- Re: et-mgmt-tools virsh failed to get local hostname
virt-install --connect=qemu:///system --name=z01 --ram=512 --vcpus=1 --disk path=/dev/LX/vol01 --os-type=linux --os-variant=rhel5 --location=nfs:192.168.42.132:/exports/isos/centos55 -x "ks=nfs:192.168.42.132:/exports/ks/anaconda-ks.cfg ip=192.168.42.31 netmask=255.255.255.0 gateway=192.168.42.132 dns=192.168.42.32" Starting install... Retrieving file .treeinfo... | 834 B 00:00 ... Retrieving file vmlinuz... | 3.7 MB 00:00 ... Retrieving file initrd.img... | 15 MB 00:00 ... Creating domain... | 0 B 00:00 error: Failed to get local hostname Domain installation still in progress. You can reconnect to the console to complete the installation process.
Kickstart issues
That directory could not be mounted from the server
A1: Wrong IP address used for NFS server. A2: The path was wrong.
- tail /var/log/messages:
- refused mount request from 192.168.42.31 for /export/isos/centos55 (/): no export entry