OSv, a new operating system for the cloud.
wkozaczuk Fixed warning in tests/misc-free-perf.cc
Fixed warning in tests/misc-free-perf.cc:70:35: warning: ‘new’ of type ‘queue_t’
 {aka ‘ring_spsc<void*, 67108864>’} with extended alignment 64 [-Waligned-new=]
  queue_t* queue2 = new queue_t();
by adding proper compiler option.

Signed-off-by: Waldemar Kozaczuk <jwkozaczuk@gmail.com>
Latest commit b0df7a7 Nov 8, 2018
Failed to load latest commit information.
apps @ d9e5aa1 Update apps submodule Oct 29, 2018
arch Implement almost-in-place kernel decompression Sep 29, 2018
bsd Fix compilation errors due to multiple sys/random.h Aug 15, 2018
compiler osv: use __ASSEMBLY__ instead of ASSEMBLY Jan 24, 2017
conf build: move arch-specific configuration to conf/$(arch).mk Jun 18, 2014
core Fix assertion failure when running shared object linked with Gold Oct 31, 2018
documentation fix permissions on LICENSE-prex Feb 6, 2018
drivers drivers/vmxnet3: Fix driver state issues Jun 18, 2018
external nfs: Add a makefile option to build in libnfs. Dec 20, 2015
fastlz Implement almost-in-place kernel decompression Sep 29, 2018
fs Add fcntl64 function Oct 28, 2018
images Remove deprecated "mgmt" submodule Jul 26, 2016
include Fix UIO_MAXIOV redefine warning when compiling some httpserver warnings Nov 5, 2018
java/jvm Move java/* to modules/java* and modularize java images build process Dec 21, 2016
libc implement __sigsetjmp() Aug 29, 2018
licenses Implemented Read-Only File System (ROFS) Mar 22, 2018
modules Fixed warning in tests/misc-free-perf.cc Nov 7, 2018
musl @ 372a948 Add musl git submodule Aug 4, 2014
scripts Added Ubuntu Bionic(18.04) to the setup script, based on Mint 19 Oct 31, 2018
static/etc Implemented Read-Only File System (ROFS) Mar 22, 2018
tests test: fix possible undefined behaviour at the loop that fills the buf… Nov 6, 2018
tools cpiod: add verbose program option Nov 8, 2017
.gitignore Added some extra files to .gitignore Jul 7, 2018
.gitmodules Split httpserver module into httpserver-api and httpserver-html5-gui Sep 10, 2017
CODINGSTYLE.md Add line breaks to CODINGSTYLE Jan 26, 2015
Doxyfile doxygen: add include strip path Sep 16, 2014
LICENSE Add LICENSE files to the main project Sep 15, 2013
Makefile Disable linking libgcc.a with --whole-archive option Oct 14, 2018
PORTING build.mk: enable first AArch64 stubbed support Apr 2, 2014
README.md README: Arch Linux: workaround for openssl-1.0 Oct 6, 2017
bootfs.S Encapsulate boot filesystem image in an object file for direct linking Dec 23, 2012
bootfs.manifest.skel Add vdso fast syscall compatibility library Mar 18, 2018
bootfs_empty.manifest.skel Changed build script to use empty bootfs for ROFS images Jul 29, 2018
config.json Remove deprecated "mgmt" submodule Jul 26, 2016
dummy-shlib.cc loader: add a dummy shared library to the build Dec 23, 2012
gen-ctype-data.cc locale: fix std::toupper(), std::tolower(), and std::regex Feb 1, 2016
linux.cc add nanosleep to syscall() Sep 16, 2018
loader.cc add boot_time event of uncompress lzloader.elf Apr 13, 2018
runtime.cc Stub implementation of mkfifoat() Aug 14, 2018
usr.manifest.skel Add vdso fast syscall compatibility library Mar 18, 2018
usr_ramfs.manifest.skel Implemented Read-Only File System (ROFS) Mar 22, 2018
usr_rofs.manifest.skel Implemented Read-Only File System (ROFS) Mar 22, 2018



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



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.

If you wish, you can run the script 'scripts/setup.py' as root to install all dependencies. Otherwise, you may follow the manual instructions below.

First, install prerequisite packages:



Debian stable(wheezy) Debian stable(wheezy) requires to compile gcc, gdb and qemu. And also need to configure bridge manually.

More details are available on wiki page: Building OSv on Debian stable

Debian testing(jessie)

apt-get install build-essential libboost-all-dev genromfs autoconf libtool openjdk-7-jdk ant qemu-utils maven libmaven-shade-plugin-java python-dpkt tcpdump gdb qemu-system-x86 gawk gnutls-bin openssl python-requests lib32stdc++-4.9-dev p11-kit

Arch Linux

pacman -S base-devel git python apache-ant maven qemu gdb boost yaml-cpp unzip openssl-1.0

Apply the following patch to make it work with openssl-1.0

diff --git a/modules/lua/Makefile b/modules/lua/Makefile
index 9676f349..ddb6a075 100644
--- a/modules/lua/Makefile
+++ b/modules/lua/Makefile
@@ -123,7 +123,7 @@ $(CDIR)/ssl.lua: $(LUA_ROCKS_BIN)
 # Workaround because LuaRocks ignores /lib64
 ifneq ("$(wildcard /usr/lib64/libssl.so*)", "")
-       out/bin/luarocks install LuaSec 0.5 OPENSSL_LIBDIR=/usr/lib64
+       out/bin/luarocks install LuaSec 0.5 OPENSSL_LIBDIR=/usr/lib/openssl-1.0 OPENSSL_INCDIR=/usr/include/openssl-1.0
        out/bin/luarocks install LuaSec 0.5

Before start building OSv, you'll need to add your account to kvm group.

usermod -aG kvm <user name>



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 4.8 or above is required, 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 --recursive

Finally, build everything at once:


to build only the OSv kernel, or more usefully,


to build an image of the OSv kernel and the default application.

scripts/build creates the image build/last/usr.img in qcow2 format. To convert this image to other formats, use the scripts/convert tool, which can create an image in the vmdk, vdi, raw, or qcow2-old formats (qcow2-old is an older qcow2 format, compatible with older versions of QEMU). For example:

scripts/convert raw

By default make will use the static libraries and headers of gcc in external submodule. To change this pass host via *_env variables:

make build_env=host

This will use static libraries and headers in the system instead (make sure they are installed before run make), if you only want to use C++ static libraries in the system, just set cxx_lib_env to host:

make cxx_lib_env=host

Running OSv


By default, this runs OSv under KVM, with 4 VCPUs and 2GB of memory, and runs the default management application containing a shell, a REST API server and a browser base dashboard (at port 8000).

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 netmask up
route add default gw

Test networking:

test invoke TCPExternalCommunication

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

# Building and running a simple java application example
$ scripts/build image=java-example
$ scripts/run.py -e "java.so -cp /java-example Hello"

# Running an ifconfig by explicit execution of ifconfig.so (compiled C++ code)
$ scripts/build
$ sudo scripts/run.py -nv -e "/tools/ifconfig.so"