Networking for storage systems of SMB sector: Part 1. Choosing network equipment

    There are various methods for organizing a centralized data storage system.
    Nevertheless, most of these techniques can somehow be reduced to one of three areas ...

    Three Ways to Storage


    The first way is to bet on widely advertised solutions from well-known brands. When the equipment of the most famous and expensive manufacturers is bought. A similar system is installed and maintained exclusively by highly paid specialists who have been trained in courses by the vendor and have passed the certificate exam.

    Such a system is quite reliable, productive and, of course, expensive.
    Of course, life dictates its compromises, but if we talk about the strategy of the approach, this is what is described above.

    An example of this approach is, for example, Dell EMC storage systems with Brocade's Fiber Channel media. Among Russian systems it is difficult to name the same well-known and "venerable" manufacturers.

    Second waylies in the acquisition of a turnkey ready-made solution. If in the first version there was some element of uncertainty at the stage of choosing a manufacturer, equipment, execution, and the like, then in the second case everything is already assembled, tested, and ready to go.

    An example of this approach is the PolyByte system from the Russian company ARSIENTEK LLC. If we talk about foreign manufacturers, it comes to mind storage as part of IBM Pure Systems.

    The third way is more or less complete control over the created system. That is, the system architect, engineer or administrator chooses the storage configuration himself, selects equipment, often from various manufacturers, relying not only on a familiar name, but also on his knowledge and experience.

    If we talk about which approach is preferable, then many factors must be taken into account. Among them:

    • How much money is budgeted?
    • What data growth is expected over a certain period of time?
    • What are the requirements for fault tolerance and minimum downtime?
    • How will data access be organized?
    • Who will mount, connect and maintain this system?
    • How will the backup be done?

    Etc.

    As you can see, this is a rather difficult task.

    Therefore, complex Enterprise-level systems gravitate toward the first two areas, in which there are fewer “dark spots” and “white spots” for the designer. At the same time, big business is ready to put up with relatively high costs in exchange for a proven approach, an extended warranty and support from the vendor.

    However, if we are talking about relatively small enterprises, which, respectively, need a not so powerful data storage system, then the situation is somewhat different.

    In this case, budget savings most often come first. The second place according to tradition is occupied by ease of implementation.

    Of course, any organization, large or small, cares about the safety of its data, the availability of access to them and the solution of such issues as the ability to increase storage volumes. But when the budget is limited and the IT infrastructure itself is not so complicated, it will be more profitable for small enterprises to independently purchase equipment and the subsequent creation of a data storage system.

    And here there are two options: buy a ready-made inexpensive storage system or make your own, based on popular solutions, for example, specialized distributions of open operating systems. Such as Linux, FreeBSD or Open Indiana.

    Data Access Network


    We missed something, right?

    All this time, they carefully considered on the basis of what to build a data storage system, but the question remained: “How to organize access to it?”

    That is, you need a network. At the same time, a network may be needed both for data exchange with client devices and for managing storage systems.

    First of all, we will determine the data transmission medium. This term refers to a purely hardware aspect - how exactly is the transfer (transfer) of a unit of information from a physical transmitter to a receiver. Today, there are two main areas:

    • Copper cable (most often twisted pair with an RJ45 connector);
    • Fiber optic (based on SFP + connector).

    NOTE . Often, a manufacturer offers a universal, or, as they say, convergent solution for a data transmission medium. In this case, the same port on the network equipment can be used either for twisted pair cable or for fiber optic connection. This versatility is achieved through the use of appropriate adapters - transceivers.

    Building a data transmission medium using fiber optics will be much more expensive. If the enterprise is small and all the equipment (both server and storage) is located in several racks or cabinets that are nearby, you can easily select a copper cable.

    Most low-cost storage systems are designed for use in local IP networks based on the Ethernet family and much less often based on the Fiber Channel standard using appropriate equipment (fabric).

    The situation is similar in popular distributions for building makeshift storage systems, such as FreeNAS. For such solutions, IP networks are the primary or even the only working environment.

    Now it remains to choose equipment. You can give preference to devices from well-known, widely publicized brands, such as Cisco, Brocade, Juniper.

    This option is good because there is no need to ask questions of reliability, performance, as well as searching for information on tuning, maintenance, and so on.

    The downside is the fact that the purchase of such equipment negates all previous efforts to save. It makes little sense to create a low-cost storage system if you eventually need to purchase expensive devices for network access. Wouldn’t it be more logical to immediately follow the first path described in the introductory part of this article and build storage systems exclusively on hardware from well-known brands or just buy a turnkey solution?

    The second option at first glance seems not so simple - to choose reliable, productive, but at the same time inexpensive equipment from a less "untwisted" manufacturer. It is important here to immediately determine the necessary parameters.

    Criteria for selecting network equipment for budget storage


    Since we are talking about building a network for storage and access to data, issues of performance and fault tolerance come to the fore.

    It is imperative that the switches have good internal hardware, first of all, a specialized productive processor and a sufficient amount of RAM. Equally important is an operating system optimized for the corresponding tasks.

    If we talk about data transfer rates, then 10 Gigabit Ethernet looks like the best solution for today. 10GBE network cards have long been built into server motherboards. Often 1 Gigabit Ethernet is used only for connecting workstations, and on server hardware it is less and less common.

    Interfaces 40 Gigabit Ethernet and 100 Gigabit Ethernet are not used so often. I have not yet seen the 40 GBE embedded in server motherboards.

    Based on this, requirements for the manufacturer are looming.

    This should not be NoName equipment or from a lower price category. Devices from little-known vendors are applicable only after extended testing for fault tolerance and MTBF.

    Despite the fact that the withdrawal of support and other troubles for the switches in the event of the operation of anti-Russian sanctions are not so critical, still you should not fall for it. Another point: sanctions can complicate the purchase of equipment in addition to those already in operation, and you still have to look for another manufacturer and set up a “zoo”.

    If you don’t want to get such problems, you can choose equipment from Russian manufacturers or search among vendors who do not support sanctions against Russia.

    It is worth noting the fact that Russian companies relatively recently began to work actively in this market segment. If we are talking about access level switches, for example, to connect workstations to the network, then taking advantage of the offer of Russian companies is a very good idea. But networked storage infrastructure requires fast, proven solutions. The issue price in the event of a failure and subsequent data loss can be very high.

    You can buy or take several domestic devices for testing and conduct independent research. But how long can it take, not to mention other resources?

    Therefore, it is better to use proven solutions from vendors who are loyal to Russia and have managed to gain some popularity. The most famous are now HUAWEI and Zyxel.

    Unfortunately, HUAWEI was unable to find switches with ports exclusively for copper twisted pair conductors. The use of transceivers (adapters) involves additional costs.

    But Zyxel has two interesting series of 10 GBE switches with copper ports:
    12-port 10GbE Smart Switch - XS1920 Series
    24-port 10GbE L2 + Switch - XS3700 Series


    Zyxel XS1920-12 Switch

    For building low-cost networks of small organizations, the option with the 12-port Zyxel XS1920 Series looks quite interesting: low price combined with good hardware component:

    • Processor - CAVIUM 7010 800MHZ. [5]
    • RAM is 128Mb.

    The firmware used is the Zyxel development operating system - ZyNOS V4.30 ((AASR.1) C0), a specialized operating system for managing switches.
    Among the standard functions useful when organizing storage systems: Jumbo Frame, VLAN and LAG are present in this device.

    Instead of a conclusion


    Creating your own storage system that meets your requirements is not so simple, but quite possible.

    One of the main issues is the competent statement of the problem and the selection of equipment for its implementation. As you can see, the modern network equipment market is ready to provide the right solution.

    The next article will discuss the practical aspects of building small storage networks.

    Sources



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