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===== KVM =====
==== Crear imagen ====
<code>
qemu-img create -f qcow2 image.img 10G
</code>
==== Get images info ====
<code>
qemu-img info /route/example.img
</code>
==== Convert image from qcow2 to raw ====
<code>
qemu-img convert -f qcow1 -O raw /var/lib/libvirt/images/kvm2.img /var/lib/libvirt/images/kvm2_new.img
qemu-img convert -f vpc -O qcow2
</code>
==== Snapshots ====
<code>
qemu-img create -f qcow2 -F qcow2 -b win10.qcow2 win10_UOC_DB.img
</code>

=== KVM con I/O iscsi paravirtualizado soporte trim optimizados ceros y teclado español===

<code>
qemu-system-x86_64 -enable-kvm -m 4000  -device virtio-scsi-pci,id=scsi -device scsi-hd,drive=hd  -drive if=none,discard=on,detect-zeroes=on,file=debian.cow,id=hd -k es
</code>

=== KVM con I/O paravirtualizado y escritorio remoto spice ===
<code>
 kvm -m 512  -drive file=iso/linuxmint-14.1-mate-dvd-32bit.iso,if=virtio -net nic,model=virtio -net user -vga qxl -spice port=5900,addr=155.210.47.75,disable-ticketing
</code>

==== Screen + KVM ====
<code bash>
cd /mnt/datos/  && screen -S Nagios -d -m kvm  -curses nagios.img -redir tcp:11022::22 -redir tcp:11080::80 
cd /mnt/datos/  && screen -S XP -d -m kvm -m 350  -nographic -usbdevice tablet  xp.img -redir tcp:3389::3389
</code>
==== montar imagenes raw vmdk qcow ====

<code>
modprobe nbd max_part=16
qemu-nbd -c /dev/nbd0 cosa.vmdk
partprobe /dev/nbd0
mount /dev/nbd0p1 mnt
</code>

=== Si hay lvm ===
<code>
vgscan
vgchange -a y
</code>

==== Ubuntu + KVM + VNC ====
  * El arranque correcto con vnc requiere quitar de la linea boot la opción "splash"

==== KVM con BIOS uefi ====

<code>
kvm -bios /usr/share/ovmf/OVMF.fd -m 2G cosa.img
</code>
==== Modos de red ====
  * + info http://www.linux-kvm.org/page/Networking

=== User Networking ===

**Cuando usar:**    
    * Un modo simple para que la máquina virtual tenga acceso al host, a internet y a recursos de la red local
    * No se va a necesitar acceder a la máquina virtual desde la red o desde otra máquina
    * You are ready to take a huge performance hit.
    * Warning: User networking does not support a number of networking features like ICMP. Certain applications (like ping) may not function properly. 
**Modo de uso**
<code bash> kvm -net nic -net user /path/to/hda.img </code>
=== Private Virtual Bridge ===
**Cuando usar:**    
    * Se quiere crear una red virtual entre dos máquinas virtuales
=== Public Bridge ===
**Cuando usar:** 
  * Se quiere asignar una IP a la máquina virtual y se quiere que sea accesible desde la red. 
** ¿Ejemplo?**
<code bash>
etfiat@debian-brutal:~$ cat puentes
#puente y tap
brctl addbr br0
ifconfig br0 192.168.0.1 up
#apt-get install uml-utilities
tunctl -b -u  etfiat -t tap1
ifconfig tap1
#brctl addif br0 tap1

#nat

#permitimos redirección
echo 1 >  /proc/sys/net/ipv4/ip_forward

iptables -F
iptables -t nat -F
iptables -t nat -A POSTROUTING -o eth0 -j SNAT --to 155.210.47.75

#maquina virtual
kvm -hda debian.img   -m 256 -net nic,macaddr=52:54:00:12:34:50,vlan=0 -net tap,vlan=0,ifname=tap1 # -nographic

#bajada de puente y tap
brctl delif br0 tap1
ifconfig br0 down
brctl delbr br0
tunctl -d tap1

etfiat@debian-brutal:~$ cat /etc/kvm/kvm-ifup
#!/bin/sh

switch=$(ip route ls | awk '/^default / { for(i=0;i<NF;i++) { if ($(i) == "dev") print $(i+1) }}')
switch=br0
/sbin/ifconfig $1 0.0.0.0 up
/usr/sbin/brctl addif ${switch} $1
exit 0
</code>

<code>
kvm -cdrom debian-8.3.0-amd64-netinst.iso  -net bridge -net nic,model=virtio -drive file=/dev/sdh,format=raw -m 2048

kvm -cdrom debian.iso  -net bridge -net nic,model=virtio -drive file=/dev/sdh,format=raw -m 2048

kvm -drive file=debian.img,if=virtio -drive file=debian.iso,if=virtio,media=cdrom

kvm  -drive file=debian-8.3.0-amd64-netinst.iso,media=cdrom  -drive file=debian.img,if=virtio,format=raw -m 2048 -net bridge -net nic,model=virtio
</code>

# The loopback network interface
auto lo
iface lo inet loopback

allow-hotplug enp10s3f0
iface enp10s3f0 inet manual

auto br0
iface br0 inet static
   address 155.210.4.98
   netmask 255.255.255.240
   network 155.210.4.0
   broadcast 155.210.4.111
   gateway 155.210.4.110
   dns-nameservers 155.210.12.9 155.210.3.12
   dns-search unizar.es

bridge_ports enp10s3f0
   bridge_stp off
   bridge_fd 0
   bridge_maxwait 0

auto br1  
iface br1 inet static
        address 10.148.97.254  
        broadcast 10.148.97.255  
        netmask 255.255.255.0
        network 10.148.97.0
        dns-nameservers 155.210.12.9 155.210.3.12
        dns-search unizar.es

</code>

==== Pasar dispositivo usb a la VM ====

<code>

sudo kvm -m 4000  -cdrom Descargas/Fedora-Games-Live-x86_64-33-1.2.iso -usb --device usb-host,vendorid=0x258a,productid=0x0027

</code>

==== Bridges en interfaces con vlan ====

<code>

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
vlan-raw-device eno1

#auto eno1.516
#iface eno1.516 inet static
#       address 10.0.4.207
#       netmask 255.255.255.0
#       gateway 10.0.4.254

auto eno1.516
iface eno1.516 inet manual

auto brblades
iface brblades inet static
        address 10.0.4.207
        netmask 255.255.255.0
        gateway 10.0.4.254

bridge_ports eno1.516
        bridge_stp off
        bridge_fd 0
        bridgeç_maxwait 0

#auto eno1.1105
#iface eno1.1105 inet static
#       address 172.16.200.101
#       netmask 255.255.255.0

auto eno1.1105
iface eno1.1105 inet manual

auto brceph
        iface brceph inet static
        address 172.16.200.101
        netmask 255.255.255.0

bridge_ports eno1.1105
        bridge_stp off
        bridge_fd 0
        bridge_maxwait 0

</code>

==== Bridged network sintaxis nueva ====

<code>

qemu-system-x86_64 -enable-kvm                                                           \
 -m 4096 frontal.img                                                                      \
 -device e1000,netdev=net0,mac=DE:AD:BE:EF:00:FA                                         \
 -netdev tap,id=net0,script=/etc/kvm/kvm-brblades-ifup,downscript=/etc/kvm/kvm-ifdown    \
 -device e1000,netdev=net1,mac=DE:AD:BE:EF:00:FB                                         \
 -netdev tap,id=net1,script=/etc/kvm/kvm-brceph-iup,downscript=/etc/kvm/kvm-ifdown       \

$ cat /etc/kvm/kvm-brceph-ifup  
#!/bin/sh 
# 
# Script called by kvm on tap interface creation 
# 
KVM_BR=`basename $0 -ifup | sed -e 's/^[^-]*-\?//'` 
KVM_BRIDGE=${KVM_BR:-$KVM_BRIDGE} 
echo "$0:" 
echo "Adding $1 to bridge interface $KVM_BRIDGE" 
brctl addif "$KVM_BRIDGE" "$1" 
ip link set "$1" up

$ cat /etc/kvm/kvm-ifdown  
#!/bin/sh 
# 
# Script called by kvm on tap interface deletion 
# 
KVM_BR=`basename $0 -ifdown|sed -e 's/^[^-]*-\?//'` 
KVM_BRIDGE=${KVM_BR:-$KVM_BRIDGE} 
echo "$0:" 
echo "Removing $1 from bridge $KVM_BRIDGE" 
ip link set "$1" down 
brctl delif "$KVM_BRIDGE" "$1"

</code>

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