5. EL RENDIMIENTO ESCOLAR LA INFLUENCIA DEL ENTORNO
5.3. Análisis de resultados del modelo
5.3.2. Modelos de regresión múltiple: Nuevo León
We can’t do justice to a discussion of virtualization without discussing Citrix and VMware.
7.8.4 Citrix
Citrix has been catching a wave.
Founded in 1989 by Ed Iacobucci, a former developer for IBM, Citrix’s name is a portmanteau (blended word) of Citrus, the company’s original name, a tribute to its headquarters in Coral Springs, Florida, and UNIX.
Virtualization: Open Source and VMware 155
Citrix was an early pioneer in virtualization for PC architecture, Win- View, which provided remote access to DOS and Windows 3.1 applications on a multi-user platform. Microsoft agreed to license Citrix technology for Windows NT Server 4.0, resulting in Windows Terminal Server Edition, and Citrix agreed not to compete with a product of its own. However, it could (and did) offer extensions, which it initially called Metaframe XP and Presentation Server. The product, now called XenApp, provides application virtualization and application delivery. Citrix XenDesktop is a desktop vir- tualization and virtual desktop infrastructure (VDI) solution (see Figure 7.5) that delivers a complete Windows desktop experience as an on-demand service to any user, anywhere. In the virtual desktop market, Citrix and VMware are the main competitors.
Citrix’s XenServer, discussed below, provides server platform virtualization. First-generation VDI solutions were useful only to a narrow set of users, primarily those working all day using a small number of corporate applications.
Today, whether users are task workers, knowledge workers or mobile workers, XenDesktop can quickly and securely deliver individual applica- tions or complete desktops while providing a high-definition user experi- ence. Citrix calls its delivery technology FlexCast, and it enables IT to deliver any type of virtual desktop, on any device.
The most important benefits of the Citrix Xen Desktop are reduced administration and management costs.
7.8.5 VMware
Founded in 1998, VMware is the 800-pound gorilla in the virtualization room, with more than $2 billion in revenue. It offered its first virtualization platform (for x86 systems) in 1999. VMware was acquired by EMC in 2004, and partially spun-off from EMC in 2007, but EMC still overwhelm- ingly controls it.
Since parent EMC is a hardware vendor, primarily serving larger enter- prises, VMware not surprisingly has private, secure data centers in its DNA, and has been going, as they say about themselves, “all in” on private clouds. It is a founding sponsor of PrivateCloud.com, an industry destination for news, resources, and conversation on enterprise cloud computing that’s worth a visit. However, they are very active (through partners) in the public cloud space as well.
VMware has three offerings. vSphere™ 4 is VMware’s offering for a private cloud solution and the current incarnation of its crown jewels.
156 Implementing and Developing Cloud Computing Applications
VMware ESXi is a free hypervisor solution somewhat comparable to Citrix XenServer, while VMware Server is a hosted solution.Table 7.1 compares VMware offerings:
VMware’s special spices are a large variety of Virtual Appliances. VMware uses the term Virtual Appliance to describe the premade image that is similar to the Amazon Machine Image (AMI) described in Chapter 6, but goes a step further by allowing for preinstalled, pretested, packaged software from the VMware Virtual Appliance Marketplace. These may be highly specific. For example, the AllardSoft Secure Filetransfer Virtual Appliance is installed on a server in your own facilities to send big files securely to customers, clients, or other staff members. It integrates with your existing Active Directory or LDAP infrastructure to further assist with the deployment.
It’s but one of hundreds of Marketplace offerings.
Figure 7.5 Xen desktop technology.technology. Licensed under the GNU Free Documentation License.
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Table 7.1 Comparison of VMware offerings. © VMware, Reproduced by Permission
Essentials for Retail
Essentials Plus for
Retail Standard Advanced Enterprise
Enterprise Plus ESX/ESXi
vCenter Server Compatibility vCenter Server for Essentials, vCenter Server Foundation & vCenter Server Stan- dard vCenter Server for Essentials, vCenter Server Foundation & vCenter Server Stan- dard vCenter Server Foundation & Standard vCenter Server Founda- tion & Standard vCenter Server Founda- tion & Standard vCenter Server Founda- tion & Standard Cores per Processor 6 6 6 12 6 12 vSMPSupport 4-way 4-way 4-way 4-way 4-way 8-way
Memory Physical Server 256GB 256GB 256GB 256GB 256GB *No license limit Thin Provi- sioning
VC Agent Update Manager VMSafe158 Implementing and Developing Cloud Computing Applications vStorage APIs for Data Protection
High Avail- ability (HA) Data Recovery sold separately Hot Add Fault Toler- ance vShield Zones VMotion Storage VMotion DRS DPM **vNet- work Dis- tributed SwitchTable 7.1 Comparison of VMware offerings. © VMware, Reproduced by Permission
Essentials for Retail
Essentials Plus for
Retail Standard Advanced Enterprise
Enterprise Plus
Virtualization: Open Source and VMware 159
At this writing, VMware itself is not in the public cloud business. It partners, as we shall discuss, with many leading cloud service providers.
Paul Maritz, who retired from Microsoft after 14 years, culminating as group vice president of platform strategy, is president and CEO of VMware, and Tod Nielsen, another senior Microsoft development executive, is its chief operating officer. Since these well-regarded folks spent significant parts of their careers at Microsoft, software is obviously in their DNA, but they are more used to selling software-in-a-box and per-seat licenses than they are to selling metered pay-as-you-go cloud computing.
Perhaps for this reason, VMware has partnered with third parties who provide external cloud infrastructure as a service that can integrate seam- lessly with the internal cloud that VMware will be only too happy to sell you. vCloud Express is VMware’s Infrastructure as a Service (IaaS) offering delivered by VMware’s third-party service provider partners. It provides reli- able, on-demand, pay-as-you-go infrastructure that ensures compatibility with internal VMware environments and with VMware Virtualized™ ser- vices. VMware’s partners include
Bluelock (http://vcloudexpress.bluelock.com/) Hosting.com (www.hosting.com/vcloudexpress) Terremark (http://vcloudexpress.terremark.com/) Host Profiles
Third Party Multipath- ing* VMware ESX4.0 and ESXi 4.0 currently provide technical support for up to 1TB of memory. Review the vSphere 4 Configuration Maximums document ((http://www.vmware.com/pdf/ vsphere4/r40/vsp_40_config_max.pdf)) for more information.
**Enabler for third-party switch support.
Table 7.1 Comparison of VMware offerings. © VMware, Reproduced by Permission
Essentials for Retail
Essentials Plus for
Retail Standard Advanced Enterprise
Enterprise Plus
Of these, Terremark Worldwide, Inc. is the most established VMware partner. Founded in 1982, Terremark offers Infrastructure as a Service and owns and operates purpose-built datacenters in the United States, Europe, and Latin America, and access to massive and diverse network connectivity from more than 160 global carriers. VMware holds a six percent equity interest in Terremark, which provides carrier neutral colocation, managed services, and exchange point services to approximately 1,300 customers worldwide including many government entities from three highly special- ized data centers, or Network Access Points (NAPs), that were purpose-built and have been strategically located to provide security, reliability, power availability and connectivity.
So far, the market is with VMware, in the sense that there are more private than public clouds. However, public clouds are growing quickly and maturing rapidly. As astute observers of the IT scene and as former Microsoft executives, VMware’s management are well aware of three things: (1) Microsoft has, since its founding, derived substantially all of its revenue from software licensing, (2) Microsoft has made a huge bet on public cloud computing, which is our subject for the next chapter, and (3) Microsoft is under substantial pressure from free open source software. It will be interesting to look back in a few years to see if the largely propri- etary “software only” strategy of the dean of virtualization will prove to be the winning strategy.