OSv

OSv is a new open-source operating system for virtual-machines. OSv was designed from the ground up to execute a single application on top of a hypervisor, resulting in superior performance and effortless management when compared to traditional operating systems which were designed for a vast range of physical machines.

OSv has new APIs for new applications, but also runs unmodified Linux applications (most of Linux's ABI is supported) and in particular can run an unmodified JVM, and applications built on top of one.

For more information about OSv, see http://osv.io/ and https://github.com/cloudius-systems/osv/wiki

Documentation

• Debugging OSv
• Trace Analysis

Building

OSv can only be built on a 64-bit x86 Linux distribution. Please note that this means the "x86_64" or "amd64" version, not the 32-bit "i386" version.

First, install prerequisite packages:

Fedora

yum install ant autoconf automake boost-static gcc-c++ genromfs libvirt libtool flex bison qemu-system-x86 qemu-img

Debian

apt-get install build-essential libboost-all-dev genromfs autoconf libtool openjdk-7-jdk ant

Ubuntu users: you may use Oracle JDK if you don't want to pull too many dependencies for openjdk-7-jdk

To ensure functional C++11 support, Gcc 4.7 or above is required. Gcc 4.8 or above is recommended, as this was the first version to fully comply with the C++11 standard.

Make sure all git submodules are up-to-date:

git submodule update --init

Finally, build everything at once:

make

By default make creates image in qcow2 format. To change this pass format value via img_format variable, i.e.

make img_format=raw

Running OSv

./scripts/run.py

By default, this runs OSv under KVM, with 4 VCPUs and 1GB of memory, and runs the default management application (containing a shell, Web server, and SSH server).

If running under KVM you can terminate by hitting Ctrl+A X.

External Networking

To start osv with external networking:

sudo ./scripts/run.py -n -v

The -v is for kvm's vhost that provides better performance and its setup requires a tap and thus we use sudo.

By default OSv spawns a dhcpd that auto config the virtual nics. Static config can be done within OSv, configure networking like so:

ifconfig virtio-net0 192.168.122.100 netmask 255.255.255.0 up
route add default gw 192.168.122.1

Test networking:

test TCPExternalCommunication

Running Java or C applications that already reside within the image:

# The default Java-based shell and web server
sudo scripts/run.py -nv -m4G -e "java.so -jar /usr/mgmt/web-1.0.0.jar app prod"

# One of the unit tests (compiled C++ code)
$ sudo scripts/run.py -nv -m4G -e "/tests/tst-pipe.so"