Virtuos Operating System

This paper discusses VirtuOS, an operating system that provides virtualization of kernel. Reliability and fault resilience are among the most important characteristics of operating systems. Most traditional operating systems provide protection and isolation to user processes, but not to critical system components such as device drivers or other system code. As a result, failures in these components often lead to system failures. VirtuOS tries to solve this problem by decomposing parts of the operating system. VirtuOS uses virtualization to isolate and protect vertical slices of existing OS kernels into separate domains. There are two major domains- primary and service. Primary domain is dedicated to core system tasks such as process management, scheduling, user memory management, and IPC. Service domains do not run any user processes but are only responsible for bootstrapping and performing system management tasks and to handle requests coming from the user processes. There are two service domains in VirtuOS-storage and network. One service domain only serves a single primary domain. The primary and service domains share regions to communication. Communication is done through system calls. VirtuOS is currently implemented as a prototype based on the Linux kernel and Xen hypervisor. In most of the benchmarks VirtuOS mostly matches or exceeds that of Linux’s performance by 1-16%.

Pros-

• The explanation of their exception less system calls is good.
• This figure for architecture of VirtuOS helps better understand.
• It is clearly mentioned what system calls are not yet supported.

Cons-

• Paper doesn’t mention what the size of request quest is or how big the system call entries are.
• Paper puts limitations under implementation.