Making a template and cloning in KVM

EddieJennings

At my current job, I'm getting experience with VMware for the first time. One thing that I like about it is that we have templates of a few editions of Window Server, which we keep patched to current and from which we deploy new VMs as needed.

My home lab uses KVM, so I wanted to see if I could create similar functionality. I'm not using oVirt or anything like that (that's a project for the future), but here's what I've done and do reduce a bit of time for deploying some new VMs.

I have a VM of Fedora, which I keep patched to current. The VM is shutdown when not being patched so it's not eating resources.
To deploy a new VM, I run the following command on my KVM host.

virt-clone --original VMtoBeCloned --name VMtoBeCreated --mac RANDOM --auto-clone

According to the man page simply not specifying --mac should generate new mac addresses for the NICs, but I'm a bit paranoid. The --auto-clone option will automatically create the qcow2 storage file for the new VM.

You can also clone from the Virt Manager GUI, which is what I did until I discovered the greatness of --auto-clone.

black3dynamite

Virt-Builder is another option if you will be creating Linux VMs.
It's slow the first time you use it but the next time, its a lot quicker.

sudo virt-builder fedora-28 \
    --root-password password:Password1 \
    --output /home/kvm/libvirt/images/fedora28.qcow2 \
    --format qcow2 \
    --hostname fedora28.domain.com \
    --timezone America/Denver \
    --update \
    --install cockpit \
    --install cockpit-storaged \
    --selinux-relabel \
    --size 50G \
    --firstboot-command 'systemctl enable --now cockpit.socket' \
    --firstboot-command 'firewall-cmd --permanent --add-service=cockpit; firewall-cmd --reload'

sudo virt-install \
    --name fedora28 \
    --vcpus 2 \
    --ram 4096 \
    --disk /home/kvm/libvirt/images/fedora28.qcow2,format=qcow2 \
    --nographics \
    --import \
    --os-variant fedora28 \
    --network type=direct,source=team0,source_mode=bridge

Obsolesce

I've been using this to set up some test VMs on KVM. It's been working great.

virt-install --name Win2016a \
--description 'Windows Server 2016 Test' \
--ram 4096 \
--vcpus 2 \
--os-type Windows \
--os-variant "win2k16" \
--disk path=/DATA/vms/Win2016a/Win2016a.qcow2,bus=sata,size=50 \
--cdrom /DATA/img/WS2016_EVAL_14393.0.161119-1705.RS1_REFRESH_SERVER_EVAL_X64FRE_EN-US.ISO \
--network type=direct,source=eth0,source_mode=bridge,model=e1000 \
--graphics spice \
--noautoconsole \
--noreboot \
--boot uefi \

Obsolesce

@obsolesce said in Making a template and cloning in KVM:

I've been using this to set up some test VMs on KVM. It's been working great.

virt-install --name Win2016a \
--description 'Windows Server 2016 Test' \
--ram 4096 \
--vcpus 2 \
--os-type Windows \
--os-variant "win2k16" \
--disk path=/DATA/vms/Win2016a/Win2016a.qcow2,bus=sata,size=50 \
--cdrom /DATA/img/WS2016_EVAL_14393.0.161119-1705.RS1_REFRESH_SERVER_EVAL_X64FRE_EN-US.ISO \
--network type=direct,source=eth0,source_mode=bridge,model=e1000 \
--graphics spice \
--noautoconsole \
--noreboot \
--boot uefi \

Something to note:

If you use --cdrom instead of --disk /path/to/iso,device=cdrom,etc..., then it will auto-boot afterwards even if using --noreboot.

stacksofplates

Started a new job last month and it's all VMware. I miss libguestfs tools.

jmoore

@stacksofplates I can imagine. Good luck!