OSv

{{about|the operating system|other uses of "OSV"|OSV (disambiguation)}}

{{Infobox OS

| developer = Cloudius Systems

| source model = Open source

| marketing target = Cloud computing

| kernel type = Unikernel

| ui = CLI, web

| released = {{Start date and age|2013|09|16}}

| programmed in = C++

| userland = POSIX, Java, Ruby

| supported platforms = x86-64 using the KVM, Xen, VMware, and VirtualBox hypervisors. (arm64 on KVM is under development)

| license = BSD license

| language = Multilingual

| working state = Stable

| website = {{URL|http://osv.io/}}

}}

OSv (stylized OS^v) is a cloud computing focused{{cite web | url=http://www.linux.com/news/enterprise/cloud-computing/751156-are-cloud-operating-systems-the-next-big-thing- | title=Are Cloud Operating Systems the Next Big Thing? | url-status=dead | archive-url=https://web.archive.org/web/20140801202943/http://www.linux.com/news/enterprise/cloud-computing/751156-are-cloud-operating-systems-the-next-big-thing- | archive-date=2014-08-01 | work=linux.com | date=3 December 2013 | accessdate=5 December 2013 | last=Kurth | first=Lars}} computer operating system released on September 16, 2013. It is a special-purpose operating system built to run as a guest on top of a virtual machine, thus it does not include drivers for bare-metal hardware.

It is a unikernel, designed to run a single Linux executable or an application written in one of the supported runtime environments (such as Java).{{cite web | url= http://queue.acm.org/detail.cfm?id=2566628 | title=Unikernels: Rise of the Virtual Library Operating System | work= ACM Queue | date=12 January 2014 | accessdate=20 May 2014 |last1=Madhavapeddy |first1=Anil |last2=Scott |first2=David J. |name-list-style=amp }} For this reason, it does not support a notion of users (it's not a multiuser system) or processes - everything runs in a single address space,{{cite web | url=http://ostatic.com/blog/cloudius-systems-announced-osv-an-operating-system-for-the-cloud | title=Cloudius Systems Announced OSv, an Operating System for the Cloud | work=OStatic | date=18 September 2013 | accessdate=11 March 2014 | last=Buys | first=Jon | url-status=dead | archiveurl=https://web.archive.org/web/20131127174128/http://ostatic.com/blog/cloudius-systems-announced-osv-an-operating-system-for-the-cloud | archivedate=27 November 2013 }} there is no difference between users address space and kernel address space. Using a single address space removes some of the time-consuming operations associated with context switching.{{cite web | url=//lwn.net/Articles/567222/ | title=Rethinking the guest operating system | work=LWN.net | date=18 September 2013 | accessdate=28 September 2013 | last=Corbet | first=Jonathan}}

It uses large amounts of code from the FreeBSD operating system, in particular the network stack and the ZFS file system. OSv can be managed using a REST Management API and an optional command-line interface written in Lua.