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Methodologies, strategies and experiences Virtualization 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 resources 1
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Methodologies, strategies and experiences Virtualization
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
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
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
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
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
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)
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
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
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
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>
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