Methodologies, strategies and experiences

1. Methodologies, strategies and experiences Virtualization

2. Definition • the abstraction of computer resources • a technique for hiding the physical characteristics of computing resources from the way in which other systems, applications, or end users interact with those resources1 1Enterprise Management Associates

3. Types and Players • Emulation - simulates complete hardware • Wine/Crossover • Hardware - simulates enough hardware • VMWare Workstation • Para-Virtualization - no hardware emulation, uses special API • Xen, VMWare ESX, User Mode Linux • OS-Virtualization - OS allows multiple secure virtual servers • Solaris Zones, BSD Jails, Linux-Vserver

4. Advantages • Consolidation (of course!) • Cost cutting via: • People resources - arguable • Hardware resources • Security - depends on type • Rapid reboot of virtual environment • Rapid deployment of another environment • Cloning - rapid test environment

5. Considerations • Shared memory - changes coming soon • Storage • The kitchen sink effect • Patch deployment / multiple versions • Positive or negative? • Many virtualization systems suffer from performance loss on some types of workloads (most loss found to be related to network and disk intensive tasks) • Solaris Zones does not suffer from this

6. Xen • Para-virtualization • Primarily modified Linux and NetBSD systems as host system • Support for various Linux and BSD, OpenSolaris, Netware as guests • Version 3.0 unmodified Windows ok(?) • Can run multiple guest operating systems • Commercial support available from XenSource • Full virtualization now available with new hardware • Can migrate live domains to new hosts

7. VMWare • Server (formerly GSX) • Para-virtualization, Windows/Linux host OS • Support for various guest OS • Can run multiple guest OS • Free! - but need to buy add-ons for some features • ESX • Full virtualization • Support for various guest OS • Can run multiple guest OS • Expensive ($5K+ for full version per physical system)

8. Solaris Zones • Operating system-level virtualization • Included with Solaris 10 • Global zone vs Non-global zones • Global zone runs kernel • Global zone contains and used to administer non-global zones • Non-global zones can be given access to devices • Non-global zones cannot export filesystems via NFS • Non-global zones can be whole or sparse • Whole zones include own copy of all filesystems • Sparse zones share filesystems such as /usr with global zone • Sparse zones can take as little as 50-100MB

9. Architecture Considerations • Solaris zones setup as sparse to save on disk space • Patching installed globally to all zones • Each zone has /zones for local files

10. Where we are - Solaris Zones • All Solaris 10 servers setup with zones • Running on multiple hardware platforms • Global zone only used for server administration • All applications run on non-global zones • Zones setup as sparse zones • Largest implementation is on a T2000 with 8 non-global zones

11. Where we are - Xen/VMWare • All Xen servers run ubuntu • Hardware platforms include Sun x2100, x4x00 • System setup to clone zones • VMWare used primarily on streaming services (Windows based) • Using virtualization as a tool for change/revision management <shameless plug> • more information on change/revision management at Ramon’s “Pure Production” talk later this week </shameless plug>

12. Future Consideration • Private Network to manage global zones • “Real root” not accessible • Single VLAN for network booting • Virtuozzo • Solaris zone cloning • Hardware-level virtualization • Sun LDOMs will create a hardware hypervisor • VMWare ESX • PXE Boot - VMWare imaged systems