瞭解伺服器硬體的主要型別和優缺點
Learn the major types of server hardware and their pros and cons
譯 者 說
東數西算的資料儲存和計算都要靠伺服器？你真的知道資料中心裡有哪些型別的伺服器嗎？
Robert Sheldon，23 Aug 2021
伺服器承載應用程式，管理文件，處理郵件，流媒體和平臺分析功能。企業和組織可以從伺服器提供的能力和廣泛用途中獲益，但很難知道該選擇哪一類伺服器硬體。
Servers host applications， manage files， process emails， stream media and perform analytics。 Any organization can benefit from the power and versatility that servers provide， but it can be difficult to know which types of server hardware to choose。
如今市面上可購買的伺服器主要可以分成三種：機架式，刀片式和大型主機（ 大型商用伺服器 ）。大部分的IT團隊傾向機架式和刀片式伺服器去滿足其硬體需求。一些團隊選取大型主機去處理其工作負載，往往並不是因為機架式和刀片式伺服器不能勝任。
Today‘s servers are primarily available in three forms： racks， blades and mainframes。 The majority of IT teams turn to rack and blade servers to meet their server requirements。 Some teams opt for mainframe computers to handle their workloads， although not nearly to the extent of rack and blade servers。
這三種伺服器都有其優劣勢，採購方應該在決定前仔細權衡這些不同型別的伺服器硬體。採購方無需限制只採購其中任意型別，然而企業和組織可以在預算和空間限制的前提下選擇最適合他們工作負載的伺服器。
Rack， blade and mainframe servers all have their advantages and disadvantages， and buyers should carefully weigh these different types of server hardware before deciding on a product。 Buyers do not need to limit their selection to any one type， however。 Organizations can choose what’s best for the workloads they need to support with an eye on budget and space constraints。
什麼是伺服器
What is a server？
伺服器是一種可以提供針對不同工作負載的計算處理和儲存資源的計算機。伺服器這個術語可以指代計算機本身或者一個提供服務的程式，例如一個郵件管理系統。大多數的伺服器硬體指物理機器。伺服器作業系統被設計用來處理大量工作負載，服務交付和支援基於網路的操作。常見的通用伺服器作業系統包括Linux， Unix和Windows Server。
A server is a type of computer that provides processing and memory resources for different workloads。 The term server can refer to the computer itself or to a program that delivers a service， such as an email management system。 Most hardware-related references concern the physical machine。 The server operating system （OS） is designed to process large workloads， deliver services and support network-based operations。 Common server OSes include Linux， Unix and Windows Server。
伺服器通常被設定用來提供一個或者多個特定的服務。伺服器通常被用來管理網路資源和連線到客戶端裝置。一臺伺服器經常被指基於它所服務的目的。例如，一個列印伺服器提供網路使用者可以使用共享的印表機，一個流媒體伺服器可以提供影片音訊內容給網路使用者。
Servers are usually set up to provide one or more specific services。 Servers are commonly used to manage network resources and make them available to client devices。 A server is often referenced to based on the purpose it serves。 For example， a print server provides network users with access to shared printers， and a media server streams video and audio content to network users。
一臺伺服器的物理硬體配置通常取決於其提供服務的類別。舉例，一個數據庫伺服器可能有更多計算處理和儲存資源去處理併發事務的飆升。許多資料中心也會進行伺服器的虛擬化以便更高效的交付服務。伺服器虛擬化能更好的幫助利用伺服器的物理資源，同時也會提高靈活性和安全性並且減少能源消耗。
A server‘s physical configuration is usually specific to the types of services it provides。 For example， a database server might include more processing or memory resources to handle the influx of concurrent transactions。 Many data centers also implement server virtualization to deliver services more efficiently。 Server virtualization can help better utilize the server’s physical resources， while also increasing flexibility and security and reducing energy consumption。
為什麼購買伺服器
Why purchase a server？
支撐大量使用者的企業和組織能從不同型別的伺服器硬體中獲益。對於大多陣列織而言，在處理業務和保護敏感資源時，伺服器是必須要的。企業組織可能在當他們新建資料中心，擴充套件和更新已有資料中心，新增辦事處和加速開發專案的時候購買伺服器。
Any organization that supports more than a handful of users can benefit from different types of server hardware。 For most organizations， servers are essential to carrying out business and protecting sensitive resources。 Organizations might need to purchase servers when they set up new data centers， expand or update existing ones， open satellite offices， or spin up development projects。
雖然伺服器增加了組織必須提供支援的計算機數量，但它們也能幫助整合資源；不同型別的伺服器硬體使得網路使用者能共享印表機、硬碟驅動器和應用程式。雖然使用者能透過點對點網路共享資源，一臺伺服器更適合被配置透過網路管理那些重要資源和安全交付，尤其是有大量使用者的情況下。
Although servers add to the number of computers that an organization must support， they can also help consolidate resources； different types of server hardware make it possible to share printers， disk drives and applications with network users。 Although users can share resources across peer-to-peer networks， a server is much better equipped to manage those resources and deliver them securely across the network， especially with a large number of users。
這種伺服器的使用方式也會因資源是中心化集中控制變得有更具生產力。這允許工作人員更好地與他們的同事共享資料。使用者能在需要的時候接觸到其所需資源而且無須擔心管理問題。例如，他們不必在他們自己的電腦系統中保留複製複製、執行和維護備份或者管理相同資料的多份複製。
This use of servers can also lead to greater productivity because resources are centralized， which allows workers to easily share data with their colleagues。 Users can access the resources they need when they need them without worrying about managing them。 For example， they do not have to keep a copy of the data on their own systems， implement and maintain a backup， or manage multiple copies of the same data。
此外，伺服器能讓使用者在遠端接觸到他們需要的應用和資料。這使得工作人員當在出差和遠端工作的時候更易保持生產力。
In addition， servers enable users to access the applications and data they need from remote locations， which makes it easier for workers to stay productive when they travel or work remotely。
伺服器也透過資料保護增加了商業價值，也提供必要的架構讓管理員去控制檔案、應用、外圍裝置和其他資源的許可權。另外，管理員能控制伺服器執行時的安全機制，透過集中監控系統應對安全及合規問題。
Servers also add business value via data protection， providing the structure necessary for admins to control which users can access files， applications， peripherals and other resources。 In addition， admins can control the security mechanisms that they implement on the servers， as well as centrally monitor systems for issues related to security and compliance。
不同型別的伺服器硬體也能更容易去備份系統和使用者資料，以及執行災難恢復策略。管理員也能更容易確保資料的可靠性和可用性，不管是透過群集化伺服器或配置冗餘部件。另外穩健的模型也使得中心化控制其他管理運營成為可能，例如維護工作站、控制域名和監控軟體。
Different types of server hardware also make it easier to back up system and user data and implement disaster recovery strategies。 Admins can also more easily ensure the reliability and availability of data， whether by clustering servers or building redundancies into system components。 In addition， the consolidated model makes it possible to centralize other management operations， such as maintaining workstations， controlling domains and monitoring software。
因為伺服器可以穩固資源，高效管理和提升生產力，他們最終能減少支出。另外他們的中心化管理能力使得更容易追蹤應用的使用情況，以便更好控制許可證支出和避免昂貴的軟體審計。
Because servers can consolidate resources， streamline management and increase productivity， they can ultimately reduce costs。 In addition， their centralized management capabilities make it easier to track application usage to better control licensing costs and avoid expensive software audits。
因為伺服器能更好地保護資料，更少可能被陷入風險，並且幫助避免高額罰款，有損聲望以及避免隨之而來的業務損失。
Because servers better protect the data， it is less likely to be compromised， helping to avoid costly fines， tarnished reputations and the lost business that comes with both of these。
機架式伺服器
Rack servers
機架式伺服器，顧名思義安裝在機架上的伺服器，是一個標準尺寸的計算機被設計安放在伺服器機架上，與其他機架式伺服器或者標準尺寸的裝置如網路裝置或儲存區的網路裝置一起。一臺機架式伺服器被認為是一個多用途的機器，能支援廣泛的工作負載。
A rack server， also known as a rack-mounted server， is a standard-size computer designed to be mounted in a server rack along with other rack servers or standard-size components， such as network or storage area network devices。 A rack server is considered to be a general-purpose machine that can support a wide range of workloads。
機架式伺服器相比塔式伺服器佔用更少的空間是因為它們沒有被包裹在大塊頭的機箱內，使用者能將其與其他裝置安裝在一個機架內。另外因為供應商標準化了機架和機架伺服器尺寸，如果其中一個裝置部件發生故障，管理者能很容易增加或者替換伺服器。這樣的設計也容易去逐漸增加部件來支援增長的工作負載。最好之處在於，在同一個機架上的伺服器不必是同一種類型或來自於同一家供應商。
Rack servers take up a lot less space than tower servers because they‘re not encased in bulky cabinets and users can stack them in a single rack along with the other components。 In addition， because providers have standardized the size of racks and rack servers， admins can easily add or replace servers if one should malfunction。 The design also makes it simple to add components gradually to accommodate growing workloads。 Best of all， the servers in the same rack don’t have to be the same model or come from the same vendor。
機架伺服器中一個最大的挑戰是管理所有把部件連線在一起的線纜。機架式伺服器需要電力、網路、管理和儲存的線纜。所有這些線纜安裝在堆疊的裝置後面，使得很難管理線纜和伺服器。線纜也能影響冷卻，機架式伺服器通常安裝的互相靠近，這進一步提出了挑戰。
One of the biggest challenges with rack servers is managing all the cabling that ties the components together。 Rack servers require cables for power， networking， management and storage， all of which hang off of the back of the stacked components， making it difficult to manage the cables and servers。 The cables can also affect cooling， which is already challenging with rack servers because of their proximity to each other。
刀鋒伺服器
Blade servers
刀鋒伺服器是一個模組化的部件 ——刀片——可和其他刀片被放入一個伺服器機箱。每一個刀片有自己的處理器、記憶體和整合的網路控制器。刀片可能也包括一個光纖通道主機匯流排介面卡，還有其他I/O 埠。相比機架伺服器，刀鋒伺服器在一個更小的空間提供更多計算處理能力，有簡化的佈線結構。
A blade server is a modular component —— blade —— that fits into a server chassis along with other blades。 Each blade has its own processors， memory and integrated network controllers。 The blade might also include a Fibre Channel host bus adapter， as well as other I/O ports。 Blade servers offer more processing power in a smaller space than rack servers while providing a simplified cabling structure。
因為在機箱中刀片式很緊湊的配置，這個機箱本身有時也被稱作刀鋒伺服器，同時單獨的刀片被稱作模組化主機板或板卡，其實這些刀片自身就是伺服器。這是因為機箱提供了穩定的資源諸如電力、冷卻和網路。這些資源被共享然後連通到所有在裡面的刀鋒伺服器。管理員也能把機箱固定在一個標準尺寸的伺服器機架上。
Because blades are so tightly configured within the chassis， the chassis itself is sometimes referred to as the blade server and the individual blades are called modular motherboards or circuit boards even though they‘re servers in their own right。 This is because the chassis provides consolidated resources such as power， cooling and networking， which are shared across all the blades within the chassis。 Admins can also mount the chassis on a standard-size server rack。
相比機架式伺服器，刀鋒伺服器其中一個最大的優勢是它能在一個更小的空間裡提供更多的計算處理密度。這使刀鋒伺服器有更好的價效比優勢，即便刀鋒伺服器比機架伺服器更貴。高效的空間使用可增加冗餘去更好地確保應用程式及資料的可靠性和可用性。
One of the biggest advantages of a blade server compared to a rack server is its ability to provide greater processing density within a smaller space。 This can result in a price-to-performance advantage even though blade servers are themselves more expensive than rack servers。 This efficient use of space can increase redundancy to better ensure the reliability and availability of applications and data。
另外，刀片和機箱部件是可以熱交換的，包括冷卻系統，控制器和交換機。由於機箱的結構，相比機架伺服器佈線更加容易。刀片系統也提供了一箇中心化的管理控制檯去控制和監控系統的部件。
In addition， the blades and chassis components are hot-swappable， including the cooling system， controllers and switches。 Plus， because of the chassis structure， cabling is simpler when compared to the rack server。 The blade system also provides a centralized management console to control and monitor the system’s components。
雖然刀鋒伺服器提供先進的計算能力，也會伴隨一些缺點，例如，伺服器機箱和刀片的架構是專用的，這使得供應商限制了更多的可能性，這個專用機型自己也會因供應商不再發布新品或者未能及時更新部件，從而限制了升級。
Although blade servers offer state-of-the-art computing capabilities， they also come with a few drawbacks。 For example， the server chassis and blade architecture are proprietary， which makes vendor lock-in a strong possibility。 This proprietary nature can also limit upgrade options if the vendor does not release new or updated components in a timely manner。
雖然刀鋒伺服器比機架伺服器更貴，在特定場景下節省了空間、電力以及管理成本上彌補費用。但機架伺服器提供一個更低的准入費用，這能滿足一個組織循序漸進業務增長的需求。對於刀鋒伺服器，企業和組織可能需要去對資料中心進行整改以適配電力和冷卻的需要。
Although blade servers are more expensive than rack servers， savings in space， power and management can offset expenses under the right circumstances。 However， the rack server provides a lower entry cost， which can be an advantage to an organization that wants to start out small and work its way up gradually。 Also， with blade servers， an organization might need to update its data center to accommodate power and cooling needs。
儘管有這些顧慮之處，一個刀鋒伺服器能成為特定場景的一個合適選項，尤其適合在空間受限的高密度伺服器機房的資料中心裡。刀鋒伺服器很適合一個需要伺服器叢集的單獨任務如檔案共享、網頁主機、流媒體、資料庫管理和虛擬桌面基礎設施。
Despite these concerns， a blade server can be a good fit in a number of circumstances， particularly for data centers with high-density server rooms in which space is limited。 Blade servers are well-suited to a single task that requires clustered servers， such as file sharing， web hosting， video streaming， database management or virtual desktop infrastructure。
大型主機
Mainframe servers
大型主機是一個特別強大的計算機；尺寸像一個大的冰箱。不像它以前能夠佔滿整個房間的樣子，如今的大型機更加緊湊和功能強大，包括非常複雜的加密能力以及多層級冗餘。大型機仍然在體積上比機架式和刀片式伺服器大很多，價格也貴很多。然而大型機也比它們功能更加強大和可靠。
A mainframe server is an extremely powerful computer； it‘s about the size of a large refrigerator。 Unlike its predecessors， which could take up an entire room， today’s mainframes are much more compact and powerful and include sophisticated encryptioncapabilities， as well as multiple layers of redundancy。 Mainframes are still much bigger and bulkier than rack or blade servers， as well as a lot more expensive。 However， mainframes are also much more powerful and reliable than anything else out there。
大型主機被設計用來高吞吐量場景；它在不影響效能情況下能支援大量的同步事務處理和高I/O負載。IBM在大型主機市場中領先，其生產的系統每天能執行120億加密事務處理。
A mainframe is designed for high throughput； it can support a large number of simultaneous transactions and heavy I/O loads without affecting performance。 IBM leads the way in the mainframe market， producing systems that can perform 12 billion encrypted transactions per day。
另外大型主機因其巨量的事務處理能力，通常是可配置的，可支援動態重新配置和提供熱交換硬體部件。一個大型主機通常執行它自己的作業系統，例如IBM的 z/OS，但近期推出的模型機也支援Linux，執行在裸金屬或虛擬機器上，極大增加了大型機的能力。
In addition to its massive transaction processing capabilities， a mainframe is extremely configurable， supports dynamic reconfigurations and provides hot-swappable hardware components。 A mainframe normally runs its own OS， such as IBM‘s z/OS， but recent models also support Linux， running on bare metal or in virtual machines， considerably increasing the mainframe’s capabilities。
大型主機享有彈性的、可靠和安全的美譽，包括一些最先進的硬體技術。多層級冗餘的存在貫穿系統以保證持續的可靠和可用性。另外，管理員甚至能部署大型機叢集去交付更高的可靠和可用性。特別是叢集在地理上是分散的，這能幫助保護防止在任何一處發生災難的影響。
Mainframes have a reputation for being resilient， reliable and secure， incorporating some of the most advanced hardware technologies available。 Multiple layers of redundancy exist throughout the system to ensure continuous reliability and availability。 In addition， admins can cluster mainframes to deliver even greater reliability and availability， especially if the cluster is geographically dispersed， which can help protect against a disaster in any one location。
大型主機主要適合高容量，資料集中的工作負載在高併發，實時事務處理的需求。例如銀行的交易或者其他金融機構。公用事業單位、政府機關和醫療保健系統也能受益於大型計算機所提供的算力。
Mainframes are primarily suited for high-volume， data-intensive workloads with many concurrent， real-time transactions， such as the transactions of banks or other financial institutions。 Industries such as utility companies， government agencies and health care systems can also benefit from the power a mainframe computer can offer。
然而，大型機的高價格標籤也意味著這不是一個給企業組織簡單試用或伺服器硬體逐漸增長業務型別的系統。一個大型主機很可能是更有長期效益，這取決於所支援的工作負載，但是初始資本開支對於許多業務來說的確太大了。
However， a mainframe‘s high price tag also means that it’s not a system for organizations that are simply testing the waters or implementing types of server hardware incrementally。 A mainframe might be more cost-effective in the long term depending on the supported workloads， but the initial capital outlay could be too much for many businesses。
大型主機也要求有經驗的技術人員去執行和操作。專注機架式和刀片式伺服器的管理員變得更加難以應對。對於許多企業組織而言，一個大型機的學習曲線可能是太陡峭以至於難以駕馭。
Mainframes also require skilled technicians to implement and operate —— a type of admin getting harder to find as much of the attention turns to rack and blade servers。 For many organizations， a mainframe comes with a learning curve that might be too steep to take on。
超融合基礎架構
Hyper-converged infrastructure
市場上的組織對於資料中心伺服器可能也考慮採用超融合基礎架構 （ HCI），這是一個以軟體為中心的系統，為了在緊湊整合的系統裡交付計算、儲存和網路資源。供應商提供超融合平臺作為獨立的裝置、純軟體的方案或者參照結構。
Organizations in the market for data center servers might also consider hyper-converged infrastructure （HCI）， a software-centric system for delivering compute， storage and networking resources in a tightly integrated system。 Vendors offer HCI platforms as self-contained appliances， software-only packages or reference architectures。
超融合平臺通常包括多個伺服器節點，利用hypervisor虛擬化每個節點的資源。一個智慧軟體層管理和協調資源貫穿各伺服器節點。另外超融合系統通常包括 嵌入的資料保護例如映象，複製或糾錯碼，還有備份，冗餘和其他容災備份能力。
An HCI platform typically consists of multiple server nodes， a hypervisor for virtualizing resources on each node， and an intelligent software layer that manages and orchestrates resources across the server nodes。 In addition， HCI systems usually include built-in data protections， such as mirroring， replication or erasure coding， as well as backup， redundancy and other disaster recovery capabilities。
組成一個HCI平臺的計算節點可以是標準的，現成的伺服器。另外對於計算處理和儲存資源，每一個伺服器也包括它自己的直接附加的儲存。大多數超融合裝置包括至少3個節點，可增加節點來適應增長的工作負載。
The compute nodes that make up an HCI platform can be standard， off-the-shelf servers。 In addition to the processing and memory resources， each server also includes its own direct-attached storage。 Most HCI appliances include at least three nodes， with the ability to add nodes to accommodate growing workloads。
智慧軟體整合了各伺服器的資源組成一個共享資源池，形成一個高靈活性和簡化的管理介面。擴充套件系統也僅僅是增加另外伺服器節點即可。伺服器節點必須是相同的，有時增加一個節點不總是為了增加計算資源，也許是處於今後擴充套件和備用的原因。
The intelligent software consolidatesthe resources from each server into a shared resource pool， delivering a high degree of flexibility while also simplifying management。 Scaling the system is merely a matter of adding another server node。 However， the server nodes must be identical， so adding a node can sometimes mean purchasing resources that are not always necessary in order to boost the compute resources。
深 知 社
翻譯：
祝葉
General Manager of ICT-Event
DKV（DeepKnowledge Volunteer）計劃成員
校對：
Plato Deng
深知社資料中心高階研究員 /DKV計劃創始成員
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