Blade Servers: A Perspective

Transcription

1 Jane Wright Technology Overview 24 October 2003 Blade s: A Perspective Summary Blade servers are evolving from low-powered models designed for Web serving to two- and four-way configurations suitable for a wider variety of applications. Table of Contents Technology Basics Technology Analysis Business Use Benefits and Risks Standards Selection Guidelines Technology Leaders Technology Alternatives Recommended Gartner Research Insight List Of Tables Table 1: Competitive Comparison: Blade Systems Table 2: Competitive Comparison: Blade Systems Table 3: Competitive Comparison: Blade Systems Gartner Reproduction of this publication in any form without prior written permission is forbidden. The information contained herein has been obtained from sources believed to be reliable. Gartner disclaims all warranties as to the accuracy, completeness or adequacy of such information. Gartner shall have no liability for errors, omissions or inadequacies in the information contained herein or for interpretations thereof. The reader assumes sole responsibility for the selection of these materials to achieve its intended results. The opinions expressed herein are subject to change without notice.

2 Technology Basics Blade servers provide a more space-efficient format compared to traditional server hardware. Sometimes called ultra dense or hyper dense servers, blade servers measure less than 1U in fact, often considerably less than 1U. More traditional (that is, nonblade) servers are deemed rack-dense if they take up about 1U for each processor in the server s configuration. (A U is an Electronics Industry Association [EIA] height unit measuring 1.75 inches, or 4.45 centimeters, of vertical space in a rack.) But blades are even slimmer, enabling a half-dozen or more blade servers, each supporting one, two or even four processors, to be installed in 1U of rack space. To achieve such densities, and to reduce the power and cooling requirements that so many processors would normally require, blade servers are not installed directly into racks. Instead, a set of blade servers are installed into specially designed chassis, enabling the blades to share some components (such as fans, power supplies, cabling and so on) within the chassis. The chassis itself is then installed into the rack. Industry standard racks are 42U high. A chassis for blade servers might measure, say, 3U to 7U in height, so a number of chassis may be installed in the rack. Although the blades share some environmental components with other blades in their chassis, blade servers are complete servers in themselves. They are, in effect, a server on a motherboard, with their own processors, cache, memory and (usually) boot disk. Many blade servers have their own input/output (I/O) slots, while some vendors have designed separate I/O blades meant to complement their compute blade servers. Blade Design To arrive at such a small size, blade server manufacturers have removed some of the components found on larger servers. For example, a blade server will typically not include a CD-ROM, a diskette drive, universal serial bus (USB), keyboard, video or mouse connections. A blade server usually consists of just the processor(s), memory, a motherboard, LAN connections, some electronic components and perhaps an internal disk drive or two. The operating system is installed on the blade(s) and mirrored to the second disk (if available). Blades often rely on external storage systems for their data requirements and are usually intended to operate in a network-attached storage (NAS) environment. Blade servers are not installed directly into the rack. Instead, a number of blades will be installed into the blade manufacturer s chassis, and it is here that the shared network connections, power supplies and cooling fans are located. The blades may be stacked vertically within the chassis, or there may be two stacks of blades positioned back to back within the chassis. Most chassis are about 3U to 7U high, with multiple chassis installed into a rack and a single keyboard and video for the entire rack. Blade Management Each blade server system has its own management software. It is this software that allows the administrator to control hundreds of blades from a single console. The management software provides the dynamic reallocation of blades (if supported), enabling customers to add and remove blades at will. This blade management tool may not be a complete server management tool, but most blade management tools have a Simple Network Management Protocol (SNMP) Management Information Base (MIB) agent that enables the blades to be monitored from a third-party management product. Blade server deployment tools enable the administrator to create an image of one blade server s configuration and then install that image on many other blades. The image is then saved for future deployment on new blades as they are added. 24 October

3 Technology Analysis hardware technology has evolved to better suit the needs of customers. Traditional server manufacturers have developed ever-smaller servers with minimal specifications, but it took some nimble startup companies to take the leap and develop the very small format of the blade server. To conserve space and reduce power and cooling requirements, early blade servers adopted some of the characteristics of a laptop computer. For example, some early blade server models utilized a laptop processor and did not support error correction code (ECC) memory. Support services for blades was minimal, with the understanding that blades were a rip out and replace product; in other words, if a blade failed, customers were expected to have extra blades on hand to quickly insert into the chassis to replace the failed blade. Now, in the second generation of blade servers, this is not always the case. Most blade servers support current server processors and chipsets with sophisticated memory technologies. Support programs for blades, while still not as generous as the standard warranties typically found on traditional servers, are providing more coverage. The quality of the blades management tools will be one key to the success or failure of the blade server technology. To succeed, a blade server s management tool must support a truly hot-pluggable environment, enabling customers to easily reallocate processing resources as requirements change. Another important key to success will be the selection of the best load-balancing, traffic management and failover products added to the stack of the blade servers. Load balancing, for example, may be implemented by Microsoft network load balancing (NLB), F5 Network s BIG-IP or Cisco s local director. The value proposition of the first blade servers to enter the market was three-pronged: savings in power, savings in space and hot-plug serviceability. Blade server customers save on power because blades require significantly less power than traditional servers. For example, a traditional, rack-dense server with one processor in a 1U format will consume 90 to 100 watts, while a blade server might consume about 10 to 15 watts. Note, however, that the total power consumption of a full rack of blade servers may be the same as, and probably more than, the total power consumption of a full rack of traditional rack-dense servers. That is, the power required per blade may be less than the power required per traditional server, but the power required per rack of blades may be about the same as the power required per rack of traditional servers. Blade servers take up less space in the racks of data centers and remote offices. For example, you can fit about 20 traditional rack-dense servers, each configured with two server processors, in a standard rack, for a total of 40 processors in the rack. Fill that rack with blade servers, on the other hand, and you can fit about 200 processors. For customers with hundreds of servers, this can lead to a significant saving in office and data center space. Blade servers, within their chassis, can be plugged into and taken out of a rack with relative ease. Because of their shared components, they require less than half the number of cables of traditional rackmounted servers. This makes blade servers easy to service. As we move forward into 2004, the value proposition for blade servers is expanding. Space savings and serviceability are still important, and customers are also demanding many of the features and some of the scalability and expandability found in traditional server products. Cost of ownership is another key factor in a blade server evaluation. Vendors and customers are attempting to quantify the point at which it becomes more economical to own a set of blade servers instead of the same number of processors installed in traditional, albeit rack-dense servers. For example, replacing one rack-dense server with one blade server would probably not yield a net cost savings, but perhaps replacing 10 rack-dense servers would. 24 October

4 One reason that costs are reduced with blade servers is that it takes relatively less time, and sometimes significantly less time, to deploy and provision a blade server compared to deploying and configuring a traditional server. Installing a traditional, rack-dense server may take hours, while installing a blade server (if the chassis is already in place) takes just minutes. But perhaps the most exciting benefit to be gained from blade servers is the ability to quickly reconfigure and redeploy them. Without blade servers, enterprises often had to purchase servers that were more powerful than they generally needed to be in order to ensure the servers had enough excess capacity to handle peaks in workload for each server s application. The result? s that were frequently underutilized. Blade servers enable customers to configure appropriately sized servers for an application s typical workload. When more resources are needed to support a temporary peak in an application s activity, the blade server administrator can pull resources from other, less busy blade servers to create a more powerful server where needed. Administrators can redeploy and repurpose blade servers manually, or the blade management software can do so dynamically based on parameters set by the customer. Of course, the blade management software that provides the redeployment and reprovisioning functions could also be executed on traditional, rack-dense servers. But redeploying or reprovisioning traditional servers also requires some physical changes to the hardware in addition to the dynamic software changes. To make changes to a traditional server s configuration, the operator must move network connections, power cables and the like. To make changes to a blade server s configuration, these physical changes are not required so long as there is an adequate pool of available resources in the chassis. For example, with traditional servers, network connections are hard-wired to specific servers. With blade servers, network switches are integrated into chassis and can be reassigned to any other blade server in the chassis with no physical movement of the connection. Thus, the capabilities of server reprovisioning software is ideally exploited by the blade server hardware format. One initial benefit touted for blade servers was the potential savings in electric power, but this has taken an unusual turn. It is true that blade servers use less electrical power and require less cooling than similarly configured, traditional rack-dense servers. Because of the greater density of blade servers, however, a fully populated rack of blade servers actually uses more electrical power than a fully populated rack of traditional servers. This has led to problems with overheating in racks of blade servers. Customers and vendors are struggling to solve this heating problem and we may even see water-cooled systems in the future. Meanwhile, if you are considering a dense farm of blade servers, be sure to carefully review the power budget and cooling requirements for your installation. Business Use Suitable applications for blade servers generally fall into two categories: front-end and midtier. Front-end applications depend more on fast throughput than on raw processing power, so they may be installed on blade servers with just one processor, and that processor may even be a low-voltage version of a server processor or a processor originally designed for a laptop computer. Front-end applications can be distributed across multiple servers with workload balancing software. Blade servers for front-end applications will need just one internal disk, or perhaps two for mirroring. Front-end applications include the following: Web serving Remote caching Proxy server Firewall 24 October

5 Encryption engines Portal services Directory servers Domain Name System (DNS) servers Thin client servers Midtier applications will require a two- or four-way blade server. These larger blade servers can support transaction-processing applications or small database applications. These applications may require more internal disks on the blade server. Because blade servers are installed in a contained location, they may be used as the home for applications that are being consolidated from a large number of stand-alone servers onto a consolidated platform. Blade servers may also work together to execute a highly complex application. In this case, they are clustered together to form a high-performance computing cluster. Applications that may take advantage of a high-performance computing cluster of blade servers include scientific and technical applications. Some blade servers are designed to fulfill a specific requirement. For example, a blade server may be optimized for Internet caching and have caching software pre-installed on it. In this case, a blade server may be seen as a server appliance on a blade. Sun s specialty blades provide an example of an appliance-like configuration on a blade format. Benefits and Risks The benefits of blade servers include: Space savings Power savings Hot-plug serviceability Ease of reconfiguration and redeployment Lower cost of ownership when high numbers of servers are involved The main risks associated with blade servers are the possibility of investing in a soon-to-be-obsolete architecture and the possibility of vendor lock-in. Many standards are being proposed and designed for the interconnect fabric between the blade servers, the chassis and the rack. The question is, Which standards will become the industry de facto standard in the future? If a customer invests in one vendor s blade server products and later finds that vendor s architecture is not the industry standard, that customer will have difficulty finding affordably priced components for the blade servers, as well as difficulty integrating those blade servers into other environments. Until the question of standards is settled, Gartner cautions customers to carefully evaluate the return on investment before investing significantly in blade servers. Standards Designing and manufacturing blade servers requires a significant investment by server vendors. Each blade server manufacturer has designed its own backplane to support its blade server models. Thus, each vendor s blade server product line is quite different from its competitors, and some server vendors 24 October

6 have no blade server offerings at all. An announcement by Intel in September 2003 could change this situation. Intel announced a set of blade server component products that will be offered by OEM vendors. As this report was written, six vendors including Bull, Ciara and Promicro had announced blade server models based on Intel s standard components, and more OEM vendors will be added in the coming months. This will increase the number of available blade server models that share common hardware formats. In fact, Intel s components were developed as part of a joint effort with IBM, and the Intel Blade server Chassis SBCE and Compute Blade SBXL52 are based on IBM s BladeCenter products. Thus, a blade server solution from Bull, for example, may be quite similar to the IBM BladeCenter. This does not mean that blade servers from an Intel OEM vendor will be supported in the IBM BladeCenter chassis, or vice versa. They may share hardware characteristics, but they will have different BIOS and firmware. In any case, the primary objective of blade server standardization, at this stage, is not to enable interoperability among the various vendors blade solutions. But having common hardware will help a great deal toward driving industry (or de facto) standards for the blade server market, which will lead to better prices and options for customers. Selection Guidelines For customers with severe space constraints, blade server density will be a key purchasing criteria. In addition, the purchasing criteria applied to traditional server investments are also important in blade server selection. Depending on application requirements, symmetrical multiprocessing (SMP) scaling, memory type and capacity, and redundant components for high availability may be equally important decision criteria. Technology Leaders Thetable Competitive Comparison: Blade Systems compares currently available blade server products from Dell, Egenera, HP, IBM, and Sun Microsystems. Table 1: Competitive Comparison: Blade Systems Dell PowerEdge 1655MC Egenera BladeFrame ES Egenera BladeFrame Number of per Blade Min./Max. Memory per Blade (bytes) 1-2 2, 4 2, 4 Intel Pentium 1.26GHz, 1.4GHz Intel 2.4GHz, 2.8GHz, 3.06GHz, 3.2GHz 128M/2G 2G/12G 2G/12G ECC Memory Yes Yes Yes Number of I/O Slots Number of in Rack Intel 2.4GHz, 2.8GHz, 3.06GHz, 3.2GHz 24 October

7 Table 1: Competitive Comparison: Blade Systems Dell PowerEdge 1655MC Egenera BladeFrame ES Egenera BladeFrame Industry- Yes No No Standard (19- inch, 42U) Rack Internal Ultra320 SCSI, No No Storage RAID optional Max. Internal Storage Capacity (bytes) 146G Not applicable Not applicable Chassis Specifications Blade PowerEdge BladeFrame ES/22.75-inches BladeFrame/84-inches high Chassis/Size 1655 Enclosure/3U high Number of Blades per Chassis Redundant, Standard Standard Standard Hot- Swappable Power Supplies Redundant, Hot- Swappable Cooling Fans Standard Standard Standard Software Specifications Operating Systems Red Hat Linux, Windows 2000 and Red Had Enterprise Linux, Window 2003, Enterprise Edition Red Had Enterprise Linux, Window 2003, Enterprise Edition Management Software Dell OpenManage, standard Egenera PAN Manager, standard and out-of-band IPMI, optional Egenera PAN Manager, standard and out-of-band IPMI, optional 24 October

8 Table 1: Competitive Comparison: Blade Systems Dell PowerEdge 1655MC Egenera BladeFrame ES Egenera BladeFrame Remote Management Software Dell OpenManage Administrator/I T Assistant Egenera PAN Manager, standard Egenera PAN Manager, standard Deployment Tool Dell OpenManage Remote Install Egenera PAN Manager Egenera PAN Manager Table 2: Competitive Comparison: Blade Systems HP ProLiant e- Class BL10e HP ProLiant P-Class BL20p G2 IBM BladeCenter HS20 Number of per Blade Intel Pentium III Intel 2.8GHz, 3.0GHz 2.6GHz, 2.8GHz 800MHz, 900MHz Min./Max. 512M-1G 512M/8G 512M/8G Memory per Blade (bytes) ECC Memory Yes Yes Yes Number of I/O None 3 2 Slots Number of in Rack Industry- Yes Yes Yes (or IBM NetBay) Standard (19- inch, 42U) Rack Internal IDE, nonhot Ultra3 SCSI, hot-pluggable IDE, hot-pluggable SCSI Storage plug Max. Internal Storage Capacity (bytes) 40G 292G 80G (IDE), 147 (SCSI) 24 October

9 Table 2: Competitive Comparison: Blade Systems HP ProLiant e- Class BL10e Chassis Specifications HP ProLiant P-Class BL20p G2 IBM BladeCenter HS20 Blade e-class Blade p-class Blade server BladeCenter/7U Chassis/Size server Enclosure/3U Enclosure/6U Number of Blades per Chassis Redundant, Standard Standard Optional Hot- Swappable Power Supplies Redundant, Hot- Swappable Cooling Fans Standard Standard Standard Software Specifications Operating Systems Windows 2000, Red Hat Linux, SuSE Linux Windows 2000,, Windows 2003, Enterprise, Red Hat Linux, SuSE Linux Windows 2000,, Red Hat Linux, SuSE Linux, NetWare Management Software Insight Manager, standard, standard Integrated Lights-Out, standard IBM Director, standard Remote Management Software Integrated Administrator, standard Integrated Administrator, standard Integrated System Management Processor, standard Deployment Tool Essentials Rapid Deployment Pack, optional Essentials Rapid Deployment Pack, standard IBM Remote Deployment Manager, optional 24 October

10 Table 3: Competitive Comparison: Blade Systems Blade 800i Blade 1200i Blade 2800i Blade 3000i Sun Fire B1600s Number of per Blade Intel LV Pentium Intel Pentium 1.2GHz Intel 2.8GHz Intel P4 3.06GHz UltraSPARC 650MHz 800MHz Level 2 Cache 512K 512K 512K 512K 512K per Processor (bytes) Min./Max. 256M/1G 256M/2G 256M/8G 256M/8G 512M/2G Memory per Blade (bytes) ECC Memory Yes Yes NA Number of I/O Slots Number of 336 (with (1) 120 (1) 224 in Rack 300ex), 252 (with 100ex) Industry- Yes Yes Yes (1) Yes (1) Yes Standard (19- inch, 42U) Rack Internal Storage IDE IDE IDE IDE IDE Max. Internal Storage Capacity (bytes) 80G 120G 120G 120G 30G Chassis Specifications Blade Chassis/Size Number of Blades per Chassis Redundant, Hot-Swappable Power Supplies Redundant, Hot-Swappable Cooling Fans 300ex/3U 300ex/3U 600ex/6U Intelligent Shelf/3U Hot-swappable, Hot-swappable, Yes Yes Yes nonredundant nonredundant No No Hot-swappable, Hot-swappable, Yes nonredundant nonredundant 24 October

11 Table 3: Competitive Comparison: Blade Systems Blade 800i Blade 1200i Blade 2800i Blade 3000i Sun Fire B1600s Software Specifications Operating Systems Management Software Remote Management Software Red Hat Linux, Windows 2000 or Red Hat Linux, Windows 2000 and Red Hat Linux, Windows 2000 and Red Hat Linux, Windows 2000 and Solaris, Linux Lights Out Manager Lights Out Manager Deployment Tool ULV: Ultra Low Voltage. Sun Provisioning 3.0 Blade Edition NA: Information not yet available from vendor. (1) Available 52U rack supports 140 processors. Technology Alternatives Traditional, Intel-based servers measuring 1U or 2U and supporting up to two processors (and thus considered rack dense ) are an alternative to blade servers. Traditional servers are appropriate for customers who, while space-constrained, can spare one rack footprint for every 40 or so processors. These traditional servers are best for front-end applications that may need more memory or more internal storage than found on blade servers or for critical applications that require a broader array of highavailability features. Blade servers may be chosen by customers who need to install over 100 processors in a single rack for front-end applications that work well in a shared storage environment. Recommended Gartner Research IBM BladeCenter Blades, DPRO Blades, DPRO HP ProLiant Blades, DPRO Insight Blade servers have come a long way since the first low-powered, uniprocessor models designed mainly for Web serving. Front-end applications are still a good fit for blade servers, while some midtier applications and high-performance computing applications have also joined the blade server repertoire. Benefits to be gained from blade servers include space savings, hot-plug serviceability, ease of 24 October

12 reprovisioning and redeployment, and, potentially, lower cost of ownership. The promise of power savings, however, has not materialized as fully populated racks of blade servers may require high levels of power and cooling. 24 October