Introduction

We have minimega installed, and we have a general idea of how to navigate the console. Let’s start some VMs.

Note: These commands are used to only start VMs on a single node. Further modules will explain how to use mesh send to do so on multiple nodes.

Downloading TinyCore

TinyCore is a very small distro of Linux that boots a GUI. The LiveCD is 16MB. You can get a copy from tinycorelinux.net/downloads.html

Copy this to your machine using wget, scp, or however you decide

Starting minimega

Let’s start minimega and attach

minimega -nostdin &
minimega -attach

Booting a VM from an ISO

Let’s call vm config and see what the configuration currently looks like

minimega:/tmp/minimega/minimega$ vm config
ubuntu: Current VM configuration:
Memory:   2048
VCPUS:    1
Networks: []
Snapshot: true
UUID:
Tags:     {}

Current KVM configuration:
Migrate Path:
Disk Paths:         []
CDROM Path:
Kernel Path:
Initrd Path:
Kernel Append:
QEMU Path:          /usr/bin/kvm
QEMU Append:        []
SerialPorts:        0
Virtio-SerialPorts: 0

Current container configuration:
Filesystem Path:
Hostname:
Init:            [/init]
Pre-init:
FIFOs:           0

By default minimega uses 2048MB of RAM for each VM; let’s change that with vm config memory

vm config memory 128

Next we’ll set the CDROM drive to use the ISO. Remember you can use tab completion.

vm config cdrom /home/ubuntu/tinycore.iso

Now let’s issue a vm config command and verify our changes.

minimega:/tmp/minimega/minimega$ vm config
ubuntu: Current VM configuration:
Memory:   128
VCPUS:    1
Networks: []
Snapshot: true
UUID:
Tags:     {}

Current KVM configuration:
Migrate Path:
Disk Paths:         []
CDROM Path:         /home/ubuntu/tinycore.iso
Kernel Path:
Initrd Path:
Kernel Append:
QEMU Path:          /usr/bin/kvm
QEMU Append:        []
SerialPorts:        0
Virtio-SerialPorts: 0

Current container configuration:
Filesystem Path:
Hostname:
Init:            [/init]
Pre-init:
FIFOs:           0

Easy enough, let’s go ahead and create the VM

vm launch kvm myfirstvm

Let’s verify it was built properly with vm info

minimega:/tmp/minimega/minimega$ vm info
host   | id | name      | state    | namespace | memory | vcpus | type | vlan | bridge | tap | mac | ip | ip6 | bandwidth | migrate | disk | snapshot | initrd | kernel | cdrom                     | append | uuid                                 | cc_active | vnc_port | tags | qos
ubuntu | 0  | myfirstvm | BUILDING |           | 128    | 1     | kvm  | []   | []     | []  | []  | [] | []  | []        |         |      | true     |        |        | /home/ubuntu/tinycore.iso |        | 4b678706-fd2f-467b-97e3-dc1ffa8ff4d0 | false     | 35096    | {}   | []

That prints a lot of stuff, let’s just get some of the columns

minimega:/tmp/minimega/minimega$ .columns name,state,snapshot,cdrom vm info
host   | name      | state    | snapshot | cdrom
ubuntu | myfirstvm | BUILDING | true     | /home/ubuntu/tinycore.iso

A VM with state BUILDING means the VM was created. A state of ERROR would mean something failed.

Now let’s start the VM with vm start and see if it is running with vm info

minimega:/tmp/minimega/minimega$ vm start myfirstvm
minimega:/tmp/minimega/minimega$ .columns name,state,snapshot,cdrom vm info
host   | name      | state   | snapshot | cdrom
ubuntu | myfirstvm | RUNNING | true     | /home/ubuntu/tinycore.iso

Congratulations, you have officially launched your first VM

Troubleshooting

If a machine fails to launch for whatever reason. You can use the vm flush command to remove the failed machine.

vm flush

If a complaint arises about missing kernel modules, you may be missing one. Refer back to the Starting and Stopping minimega module’s Bash Script section.

minimega:/tmp/minimega/minimega$ vm launch kvm myfirstvm
2016/08/25 14:49:25 ERROR kvm.go:573: vm 0 failed to connect to qmp: dial unix /tmp/minimega/0/qmp: connect: connection refused
2016/08/25 14:49:25 ERROR kvm.go:556: kill qemu: exit status 1 QEMU waiting for connection on: disconnected:unix:/tmp/minimega/0/qmp,server
Could not access KVM kernel module: No such file or directory
failed to initialize KVM: No such file or directory

Error (ubuntu): vm 0 failed to connect to qmp: dial unix /tmp/minimega/0/qmp: connect: connection refused
minimega:/tmp/minimega/minimega$ disconnect
root@ubuntu:~/minimega# sudo modprobe kvm_intel;
modprobe: ERROR: could not insert 'kvm_intel': Operation not supported
root@ubuntu:~/minimega# sudo modprobe kvm;
root@ubuntu:~/minimega# sudo modprobe openvswitch;
root@ubuntu:~/minimega# sudo modprobe 8021q;
root@ubuntu:~/minimega# sudo modprobe nbd max_part=8;

In this example minimega is unable to load kvm_intel; this was because we were running minimega in a Virtual Machine without virtualization nesting enabled.

Authors

The minimega authors