The document discusses high performant virtualization using OpenVZ. It provides an overview of different virtualization options including full virtualization, paravirtualization, and OS virtualization. It then describes OpenVZ, which uses OS-level virtualization by modifying the Linux kernel to create isolated virtual private servers on a single host OS with low overhead of 1-3%. The document outlines some limitations of OpenVZ like requiring a similar kernel, and lists features like dynamic resource management, fast provisioning of VPS, and ability to exceed allocated resources. It discusses using OpenVZ to build a private cloud with benefits like reduced hardware costs, dynamic scaling, and easy live migration between physical servers.

1. High Performant Virtualization
with OpenVZ
Nilesh Bairagi

2. Agenda
Available options in virtualization
OpenVZ introduction
Limitations
OpenVZ features
Experience of OpenVZ in private cloud
Questions

3. Full Virtualization (emulation)
Use OS as it is
Need Virtual
Machine Monitor
Performance
overhead
Low density

4. Paravirtualization
Need VMM
Better
performance than
emulator
Modified guest OS

5. OS Virtualization
Good in both
Performance
overhead and
scalability
Single OS gives
isolated
environments
Dynamic resource
management

6. OpenVZ
OS based - by modifying kernel, which enable to create
and run multiple virtual private servers (VPS) on same
host OS
VPS are isolated from each other with very little process
overhead (1 – 3%)
Processes in VPS are scheduled on all CPUs of host (by
default)

7. Limits in OpenVZ
Mandates similar kernel
 But allows multiple distributions
Limited VPN capabilities
Host is single point of failure

8. OpenVZ features
Installation has very low system requirements
 Intel Celeron, Pentium II, Pentium III, Pentium 4,
Xeon or AMD Athlon CPU, 128MB RAM, 4G free
space
Dynamic resource management
VPS – Own users & groups, process tree, ip,
network & routing, firewall etc.
VPS are efficient in utilizing resources,
therefore can exceed than actual allocated
resources

9. Features cont…
Creation of VPS in few seconds
• Use of templates enables to use pre-configured
servers (template cache)
Scaling

10. Private cloud with OpenVZ
Less number of physical servers (also reduce
cost, space and subsequent maintenance)
Capacity planning for HW
 With monitoring and trending
Resource management is dynamic, immediately
becomes effective (no reboot)
 Using packages like vzctl
Wide range of parameters to config

11. User_beancounters
Complexity abstracted by v-swap enabled kernels

12. OpenVZ cloud

13. Resource Management
Disk, CPU and memory customization
 Mounting VPS on SSD (fast read/write)
 SAN
Sharing host resources amongst CT is easy
Live migration is easy with checkpoint
Redudant VPS cost only disk space
Reproducible infrastructure

14. Questions??