Wifi home data warehouse. Building a home network

Storage systems (DSS), such as NAS, are relevant not only for small and medium-sized businesses. Their popularity is growing among home users. This is facilitated by the proliferation of UHD 4K technologies, HDR, multi-pixel matrices, our own media libraries, game libraries and libraries, video surveillance systems, in a word - everything that increases the size of files and leads to an increase in the amount of information. When creating a network attached storage, new users inevitably face the question of choosing hard drives. What should you pay attention to in order not to make a mistake when building a disk array? Let's start with a small excursion into the architecture of storage systems.

Was ist DAS? ... Ist NAS? … Ist SAN? * Which architectural solution to choose for storage?

* Literal translation from German: What is it? Is this a NAS? Is this a SAN? In this case, we are talking about a play on words - DAS is also an abbreviation of the name of one of the architectural solutions of storage.

Data storage systems (DSS) can be organized in different ways. At the moment, three storage architectures are known. Let's describe them in order of complication:

1. DAS (Direct Attached Storage). The simplest solution, in which the connection of the disk array (DM) to the server (computer) is carried out directly, i.e. without the participation of network devices. As a result, we have only two storage components connected by cable (Fig. 1) - server (no more than 2) + DM... At the same time, the disk array is a usual, albeit expandable without loss of data transfer rate, cage with disks. Due to the increasing inconsistency with modern requirements, the DAS market segment is rapidly being replaced by NAS technology.
   

   
   Rice. 1. Logical diagram of DAS connection

2. NAS (Network Attached Storage). Organization of storage systems, in which the connection of the disk array to an unlimited number of clients (servers and work computers) with different operating systems occurs via the local network. Thus, within the framework of the storage system, we see three elements (see Fig. 2): servers + local network + DM... At the same time, the disk array is no longer just a basket of disks, but a separate server with specialized software that performs the only function of a "filer", with the ability to share data via Ethernet, as well as the Internet - when the provider provides a static external IP address (see. fig. 2). Many NAS modules already allow hot swapping / adding drives without taking the server offline. In general, the functionality of NAS classes "Home" and up to the "Enterprise" segment is determined by the following set of characteristics **:

   
   the maximum supported capacity of the disk array - from 2 TB (2 × 1TB), non-expandable, up to 300 TB (30 × 10TB SATA + SSD), expandable up to 180 drives;
   read / write speed - from 100/50 Mbit / s to 5000/3500 Mbit / s;
   performance (number of input-output operations per second) - from 350 to 570,000 IOPS;
   the number of simultaneous connections (SAMBA, FTP, AFP) - from 64 to 2048;
   the number of volumes supported - from 256 to 1024;
   the number of supported types of DM management (Basic; JBOD; RAID 0; RAID 1; RAID 5; RAID 5 + Spare; RAID 6; RAID 10 (1 + 0);
   the number of supported file systems (BTRFS, EXT4, EXT3, NTFS, FAT);
   processor clock speed - from 800 MHz to 2.7 GHz (quad-core);
   the type and amount of RAM - from 256 MB (DDR3) to 128 GB (DDR4 RDIMM with error correction function);
   the type and number of network ports - from Gigabit × 1 to 10Gigabit × 4;
   support for the network file-sharing protocol iSCSI (Internet Small Computer System Interface) - on its basis, in addition to file access to data, block access is possible with the support of, for example, OpenStack Cinder;
   number of applications supported (HASP, Time Backup, Time Machine, Squeezebox, phpMyAdmin, Webalizer, VPN, Mail Station);
   support for virtualization systems (VMware, vSphere, Microsoft Hyper-X, Citrix Xen).

   
   ** Average characteristics are given for the segments "home", "small office", "medium office".
   
   Visually, the network topology (logical diagram) when using a NAS can be represented as follows:
   

   
   
   Rice. 2. Place the NAS server in the network environment

3. SAN (Storage Area Network). Complex corporate solution, different from the local network. As part of a geographically distributed storage network, it implies the ability to connect different types of storage media - from DM and virtual tape libraries based on streamers to optical drives - and is designed to work with huge amounts of data. In this case, all information carriers are perceived by operating systems as local devices. The SAN provides block (not file) access to data exclusively through servers. In its simplest form, the logical diagram of a storage network (structural cell of the network) includes 4 elements (see Fig. 3): server + switch + communication channels + storage.

Multi-switch structures, or so-called FFCs (Fiber Channel Fabric), which are a collection of switches interconnected by lines using Fiber Channel technology, can have a cascading (tree-like) topology, “ring”, “lattice” type, etc. Regardless of logical scheme in the SAN, each DM has a connection to at least two switches, and each switch to at least two servers, and the same is in reverse order. Thus, the highest SAN reliability and data availability (high availability) are achieved: in case of complete failure of one disk array, one switch, one server or one communication channel, the system will continue to function. At the same time, the number of host adapters (controllers) of the bus (HBA, Host Bus Adapter) in the server can be expanded, and at the same time, each server will receive more connections to the SAN, and the SAN itself - even greater reliability (over 99.99% ).

Rice. 3. Centrally distributed SAN topology

So, we got acquainted with three architectural solutions, in accordance with which storage systems can be built. They differ in many technical and functional parameters, but primarily in terms of cost. As you can understand, each type of organization of data storage systems is initially focused on a specific segment of the consumer. Disk arrays DAS, as a morally obsolete version of storage systems, are gradually becoming a thing of the past, although they are still in demand due to their financial availability. SANs are expensive and only available to the corporate sector.

The most promising and dynamically developing segment is NAS modules, on the principles of organization of which you can build both home and corporate storage systems. Due to their versatility and low cost, they practically replaced the classic corporate file servers, which “sinned” with additional network loads, wasted resources, and reduced the overall reliability of the network. Of course, NAS cannot compete with SANs in terms of reliability, but in many other parameters (clustering, cross-platform data synchronization with file version control) they can become their alternative.

In what options are they sold and is it possible to build storage systems on your own?

Let's start with the second part of the question. Any storage system can be designed and implemented in-house. It all depends on two factors: time and qualifications that you need to possess. Do-it-yourself network administrator skills should be as follows:

DAS is an amateur network administrator. To build a storage system of this type, it is enough to study the materials available on the Internet.
In addition to a simple instruction, you do not need to know anything: insert it - it works.
NAS is an advanced network administrator. It is necessary to have experience in assembling "hardware" and using specialized software that is involved in the management and administration of storage systems. It is required to study the instructions for connecting and using the web interface of the firmware.
SAN is a professional network administrator. In complex and geographically distributed solutions, you will have to involve a whole team of professionals who will design, select components, fine-tune, test, launch and maintain the storage network. In a domestic environment, this is irrelevant and unrealizable, therefore, it makes no sense to consider the process of building a SAN further.

Of course, much will be determined by the complexity of storage systems, since there are, for example, simple NAS solutions and complex DAS arrays.

Further, to answer the first part of the posed question, in view of the futility of DAS storage and the inaccessibility of a wide range of consumers of SAN solutions, we will consider only disk arrays based on NAS.

So, in addition to the “do-it-yourself” category, there are ready-made solutions on the market that are initially optimized by the manufacturer for working with disk arrays of a certain capacity and performance, for given speeds and topology of communication channels, for maximum network loads. NAS can be divided into two groups:

1. "All inclusive" - ​​network storages with preinstalled disk array and operating system for managing DM, factory fine-tuning of "hardware" (with the possibility of upgrading or without), additional software (with the possibility of updating and expanding or without).
2. Diskless modules are all the same, only with the ability to select and configure a disk array at your own discretion. The advantage of such products is the ability to gradually increase the number and capacity of disks within the DM.

Manufacturers of NAS modules of any of these groups focus their solutions on a specific target segment and use cases. Sometimes this division can be quite detailed, for example:

NAS class "Home" (for home use);
Small office NAS;
NAS for video surveillance systems;
NAS for business groups;
NAS for the mid-range office;
NAS class "Enterprise" (for large corporate clients).

Specifications differ in many characteristics (mentioned above), in particular, in terms of scalability (connecting new modules with disk arrays), and in the design of the case (floor-standing, desktop and "rack" options for installation in server racks).

Hard disk requirements for NAS

Of course, no one forbids putting into a diskless NAS module any storage device that fits the form factor (3.5 and / or 2.5 inches) and interface (SATA, eSATA, SAS), but then a natural question arises: Why build a NAS at all? After all, otherwise you can use a regular external large-capacity disk or a simple DAS version.

The fact is that the need for a network storage device arises when necessary:

1. remote access to files;
2. sharing data; a locally connected DAS can be shared using the Windows built-in Share service.
3. access at any time without delay;
4. frequent access to large amounts of information (for example, when one disk contains more than 12 TB of data);
5. operation of hard disks as part of a DM (one disk can also be used).

For the qualitative fulfillment of these conditions, information storage devices specialized for their fulfillment are required. Therefore, over the past decade, manufacturers have been actively developing and improving drives for building NAS arrays. They inherited many of their qualities from their older brothers - server drives used in data centers (DPC). Actually, NAS drives have become a kind of compromise between server and personal storage solutions in terms of price, speed and reliability. However, each consumer chooses for himself the characteristics of the device necessary for personal use.

But what characteristics should NAS drives have then? It will be about a set of parameters that are closely related.

First, it is reliability and work around the clock, which implies a high resistance to wear of the device. In order for the NAS disk to provide continuous readiness to transmit the requested data, the spindle drive, in comparison with a conventional disk, has a longer "timeout" for "parking" and stopping the spindle in the absence of calls to the device, i.e. it hardly stops, and the readheads of the disk do not "park". This, by the way, increases reliability, because most often problems with disks occur during start / shutdown - the heads can uncomfortably unpark / park, the spindle can jam and service information may not be written correctly when the disk is stopped. NAS disks have a high mean time between failures (MTBF) - from 1 to 3 million hours (depending on the device class), which is one third or more higher than that of "regular" ones. Device workloads range from 180 to 550 TB per year, 3-10 times more than desktop drives. From the characteristics of the reliability of the disks, the conditions of the manufacturers' warranty obligations follow - from 3 to 5 years.

Secondly, it is vibration resistance, which occurs when using HDD in a disk array. Balancing the disc in two planes can reduce vibration, but in a multi-disc environment, vibration can increase. Therefore, in NAS modules with four or more disks, it is recommended to use HDDs that additionally have rotational vibration sensors. Reduced vibration reduces wear and tear on NAS drives.

Third, it is crash protection, it is implemented by a complex of technological solutions, not only such as the absence of frequent head parking and engine stops during idle time, but also time-out during error correction. NAS drives have a special firmware, the key characteristic of which is a modified reaction to the appearance of read and write errors. If it is necessary to recover information from an unstable or bad sector, the disk, after eight seconds, notifies the RAID controller, in which it operates, that it needs help to recover the lost fragment. After that, the bad sector is reassigned, even if the S.M.A.R.T indicators remain normal. "Ordinary" disks most often "stupidly" continue to try to read, which is perceived by the RAID-array as a complete disk failure - it "crashes" from the RAID system.

Fourth, it is increased energy efficiency, thanks to which the temperature of their heating is almost two times reduced in comparison with "ordinary" hard drives. This allows drives to be installed in a relatively small and cramped NAS enclosure without fear of overheating.

NAS manufacturers assume that NAS drives will be used in their device, and not the first available HDD. Specialized models are always tested for compatibility with NAS, which means their installation and use will be as efficient and hassle-free as possible.

What to consider when choosing

Above we have outlined the requirements for most NAS drives, but what should you look for when choosing an HDD for your NAS?

Generally, it is recommended to take into account several main factors: capacity, maximum number of NAS HDDs in a RAID array, disk reliability for future workloads, security and noise levels.

Among other things, the choice of NAS disks is determined by the functional tasks for which they will be used. For example, a disk array can be used as a storage location for databases, a file server, a web server, a workstation, which, in turn, can be focused on performing video recording, image editing, game center, etc. disk performance should be dictated by the expected workload on the system at the moment and in the future, be sure to consider the scenario of its use. For a typical workload, such as recording TV shows and then playing them back, the scenario is more consistent and predictable. In atypical workloads, where data is randomly written to and read from disk, the scenario becomes more stressful and unpredictable, which affects the reliability of the operation. Reliability can also be affected by the disk interface.

Some drives use Self-Encrypting and Instant Secure Erase to provide the required level of security. Such HDDs are needed, rather, for corporate use, in companies where it is supposed to store large amounts of information for limited use.

For home NAS modules, the noise level produced by the disk array during operation becomes an essential parameter. Especially if the drive is in the same room where people sleep. Experts recommend choosing hard drives with their own low noise level during access operations and with minimal heating during operation. The cooling system of the NAS in this case will be much quieter. During linear operations, the cooler makes the main noise during operation of the NAS. Modern discs on hydraulic bearings do not make noise during linear reading. But if disk operations are predominantly "random" (random, chaotic, chaotic), then there is nothing to complain about - you can configure, for example, a caching system to speed up access to data in a torrent tracker ...

With the exception of capacity and price, some of the specific HDD parameters for NAS that are important to pay attention to are:

1. Density of recording. Each NAS HDD consists of several magnetic recording platters of various capacities - from 400 GB to 2 TB each. The more the capacity of the hard disk platters, the higher the recording density. High recording density improves disk performance, response time, if the scenario of its use, for example, streaming video, that is, with sequential read / write. If the scenario for using a DM assumes random read / write, then the write density no longer plays a significant role. However, with a higher density, the read / write heads will have to move fewer tracks for new data. Therefore, there is such a thing as Locality, i.e. proximity of data placement.
2. Spindle speed. High-speed drives for NAS arrays are considered to be devices with a spindle speed of 7200 rpm. Combined with high recording densities, these NAS drives deliver superior performance. At the same time, the high rotation speed largely compensates for the low recording density (The recording density is determined by the capabilities of the electronics of the "read / write channel" and, indeed, depends on the spindle rotation speed. But, IMHO, one should not talk about "low" density, since everything is determined by volume data that we can write / read per revolution. A fast spindle gives us a decrease in the response time of the drive to random requests, and the linear speed depends only on the number of sectors on the track and the spindle revolution time).
3. Read / write speed. It is increased by special technological solutions, for example, 2-drive head positioning system. A two-drive positioning system was needed to increase positioning accuracy with an increase in the recording density. As the tracks became so thin that the old "rocker" of the cylinder block could not be accurately kept on the track. And since the read / write speed increases with an increase in the write density - more sectors can be read in one rotation of the platter, or when the rotational speed of the platters increases, the same number of sectors are read, only in less time.
   However, as the test results say, the performance depends mainly on the bandwidth of the NAS module's network card. In addition, in a domestic environment, in order to experience all the charm of a high-bandwidth disk array, high-speed communication channels are required. At the same time, IEEE 802.11ac and Gigabit Ethernet are not able to provide it at the proper level, you will need, for example, a direct connection via Thunderbolt or already 10 Gigabit Ethernet in the entire local network, which is quite expensive to implement at home.
4. Power consumption... On the one hand, high performance drives almost always keep pace with increased power consumption. But low energy consumption leads along a chain: to lower heat generation (up to 2 ° C from the disk), to less intensive operation of coolers, to a lower noise level, to energy savings for the entire NAS system (up to 20 kWh per year based on disk). As strange as it may sound, the economy of NAS drives is more important than their performance (with rare exceptions).
5. Compatibility. Consider the compatibility of the selected HDDs with the NAS module into which they will be installed. The compatibility factor can find its expression in the lack of support by the NAS-system for the special functions of the drive, both the standard "sleep" mode, and many other proprietary functions. Compatibility must be maintained between the HDD NAS itself. For example, the type of disk management RAID 1 assumes writing data to a pair (pairs) of disks at once), and when using drives with different spindle speeds within the same partition, a faster NAS disk will constantly wait for its lagging brother to finish working. However, only when "writing" to RAID1 we are limited by the speed of a slower disk, but statistically most operations are "reads". Of course, such a configuration can also take place, but it is highly undesirable, since it deprives the RAID array of advantages.

Attention should be paid to the initial volume of the disks, since if it is necessary to replace them, the user may face serious difficulties, up to a temporary backup of all available data for transfer. In terms of cost, in almost any case, the most advantageous (but not the cheapest) one at the price of one gigabyte is the disk with the largest volume. However, the installation of such disks is not always optimal. The larger the volume of the RAID array, the longer it will take to recover when a disk is replaced or after a probable failure (sometimes more than a day).

Given the variety of options and approaches to selection, before purchasing any drives, always consult with your sales representatives, who will help you choose the “right” model for your purposes of using the NAS.

Features of Seagate Hard Drives

Three major manufacturers of NAS hard drives are Seagate, Western Digital and HGST. The rest of the eminent, but few brands, such as Toshiba, for example, are just beginning to enter this market, encountering serious competition along the way.

Seagate has been on the market since 1978, and it was she who pioneered the creation of modern types of storage with IBM.

Today, specifically for NAS, Seagate introduces two lines of hard drives based on the internal SATA 6 Gb / s interface - IronWolf ™ and IronWolf ™ Pro, each of which has several modifications (see Table 2), differing in several parameters:

capacities - from 1 TB to 12 TB;
the limit of the annual multi-user load - from 180 to 300 TB;
the maximum number of disks in a NAS system - from 8 to 16 bays;
spindle speed - 5900 and 7200 rpm;
the amount of cache memory (intermediate buffer for fast access) - from 64 to 256 MB;
throughput along the outer diameter - from 180 to 250 MB / s;
power consumption in operating mode - from 3.76 to 8.8 W;
noise characteristics in operating mode - from 21 to 32 dB;
resistance to dynamic loads - from 250 to 300 G.

Table 2. Comparative characteristics of Seagate IronWolf ™ and IronWolf ™ Pro NAS drives

Both series support Seagate AgileArray and IHM (IronWolf Health Managemen) technologies, which manage vibration compensation for multiple drives in the same storage, counteract common NAS issues and threats, and offer data recovery guidance. The design of the disk contains active sensors, the data from which is used to correct the movement of the heads during writing / reading. But it must be borne in mind that the vibration correction system in IronWolf is available only in models with a capacity of 4 TB or more.

The company focuses on network storages for offices with a capacity of up to 16 HDDs in the IronWolf Pro line, which is supplied to users with a Rescue data recovery service valid for two years (not available in all countries). We can say that it is one of the best solutions for backup, archive and disaster recovery purposes, as well as for virtualization and creating an on-premises private cloud. High-performance server solutions for hyperscale applications and data centers are implemented in the Enterprise Capacity HDD line with an annual disk load limit of up to 550 TB and an MTBF of 2.5 million hours. In flagship models, the containment area is filled with helium, which reduces the resistance to plate rotation and counteracts overheating of the heads.

Among other developments of the company, two more series can be noted:

BarraCuda (hard drives for PCs, laptops, mobile devices, DAS devices) and its game modification FireCuda;
SkyHawk (discs optimized for recording from DVRs and NVRs).

The company offers its customers not just high quality hard drives, but a whole range of solutions suitable for specific tasks. From now on, users have access to samples of high server technologies that can qualitatively improve the operation of their devices.

The amount of information stored on our computers is increasing every day. Thousands of photos, music recordings, hundreds of films and TV shows - all this at an insane speed is destroying free space on the hard drives of our computers. Buying and installing another HDD is not always a suitable solution, because a PC case may simply not have enough space, especially if you have a laptop. The use of external hard drives is often inconvenient in operation - to get it out, plug it in, etc. I would like to get access to the photo or musical composition we need without fiddling with wires, or at the same time from different devices on your network. And in such a situation, networked data storages can come to the rescue.

Stores without storage media in the kit are suitable for home use, especially if you have already purchased discs.

When using in small offices, look for more reliable and functional NAS. As a rule, such NAS are delivered without storage media, equipped with two network interfaces and more efficient hardware stuffing to cope with high load.

Definition of characteristics
The main aspect of choosing a NAS is the total volume, which comes from the capacity of drives and their number. To determine the volume, you need to consider:

1. An array of information for transferring to network storage, information on all devices on your network;
   
2. The approximate amount that you will write down in the next couple of years.
   

By adding these two values ​​(and adding 25% reserve), you will find out the approximate amount of NAS drives. The minimum size is 2 TB, it is only suitable for storing photos, music and documents. But to ensure backup, this volume is no longer enough, especially if there is more than one computer on the network.

The optimal solution for home use - NAS with a volume of 4 - 6 TB. This is guaranteed to be enough for both backups from 2-3 computers and for storing multimedia files.

Are you a professional photographer or just a passionate hobbyist? Then you definitely cannot do without network storage for storing your work and for backing up just filmed and not yet processed material. Believe me, the loss of photos due to hard drive failure is not rare, and the lack of a backup will put an end to all the work of the photographer's team. So a 6-8 TB NAS is a great storage and backup solution.

The number of drives installed affects not only the maximum amount of network storage, but also the ability to create RAID arrays for increased performance or fault tolerance. For example, support for RAID 1 (mirrored) or RAID 5 can help protect against data loss. In the first case, the network attached storage requires at least two hard disks (the disk system available to the user will be equal to the volume of one disk), and in the second case, at least three disks (also part of the disk space will be allocated for service needs). This configuration allows you to save information in the event of a breakdown of one of the disks.

Software functions
Owners of "smart" TVs will need the UPnP / DLNA server function to view media content without having to save it to the device.

NAS can be used not only as a large hard drive connected to a network. Separate devices allow the installation of additional applications, such as torrent tracker, various download managers, dropbox, etc. This will greatly expand the capabilities of your NAS.

Another interesting feature of network storages is support for ip-video surveillance for organizing a video archive and eliminates the need to purchase a separate video recorder.

Outcomes

Choosing a NAS can be boiled down to a few simple steps:

1. Do I need a storage device in the kit. If so, is one sufficient, or two or more are needed to provide more capacity or increased fault tolerance.
   
2. Determine the amount of disk space you need
   
3. Determine what additional functions and tasks the NAS will perform and make sure that they are present in the selected samples.
   

NAS - what is it and why do I need it at home?

It is impossible to imagine the modern world without every second growing colossal volumes of all kinds of information. Arrays of data from numerous data centers are hard to even imagine. The data that is stored on servers represents a wide variety of information necessary for the needs of business, scientific structures, government agencies, and so on.

However, not only large organizations need to store and use large amounts of data. Most ordinary users are already faced with the constant problem of insufficient disk space on home computers. Not so long ago, a 100 GB hard drive was an unattainable dream for most PC owners and its happy owners were lost, not knowing how to fill this abyss now. A dozen years before that, 120 MB hard drives were the ultimate dream. A dozen years earlier, popular rumor attributed to Bill Gates the words "I do not know why more than 64 kilobytes of RAM may be needed", and the information was stored on magnetic tapes and on floppy disks.

Not much time has passed on a historical scale, and a huge number of PC users, even for home storage, no longer have enough terabyte hard drives. The reason is simple: the bulk of the information stored at home is all kinds of multimedia data. Movies, music, photos every year take up more and more disk space due to the increasing requirements for picture and sound quality. If at the dawn of home multimedia a compressed movie took up to 700 MB (one CD), and an uncompressed one in DVD-quality - up to 4.7 GB, now the same Full HD movie can take up 30-40 GB on a hard disk ... If you have the ability to watch 3D video at home, then the file sizes with video content will immediately double.

Obviously, it becomes difficult to compose an extensive home video library, having one or two terabytes of storage at its disposal. The most obvious way out of this situation seems to be a simple increase in the number of hard drives in your system unit. A couple of terabytes are missing - add another disk, then another and another. As a result, it is quite possible to create a storage volume of 8-12 TB in a home PC, which will suit most users. But this solution has a number of significant disadvantages.

A typical example of a home network

Firstly, most modern apartments already have not one, but often not two devices for watching video. Computer, TVs in the living room and in the kitchen, acoustics on the loggia, etc. Each of these content consumers must have constant access to the storage. In addition, if a video surveillance system is installed in the house, the data received from the cameras can also be conveniently stored in a centralized storage. Consequently, the computer in which this storage is organized must constantly work. This is not always convenient and leads to excessive depreciation and premature failure of expensive PC components.

Secondly, the constant access of several consumers at the same time to the storage inevitably leads to a slowdown in the computer, which has to take away some of its own resources to process these calls and distribute information.

Thirdly, three or four hard drives in one system unit are quite a serious load for the power supply and a good source of heat inside the PC case. Most likely, to ensure their normal operation, you will have to replace the power supply unit with a more powerful one and organize additional cooling inside the system unit, which will inevitably lead to an increase in the noise level from the computer.

Fourth, the option of increasing storage by increasing the number of hard drives is completely impossible for those who only use laptops, tablets and similar small-sized gadgets at home. In a laptop, you can change one hard drive for another, larger capacity, but it will not be possible to radically solve the problem of limited disk space.

The solution to the problem of lack of disk space and to organize a stable and efficient operation of the home network can be the installation of a home data server. In addition to storing data, the server can be configured to perform a number of additional tasks - mail and torrent clients, home media centers, video galleries, etc. But full-fledged server solutions are still prohibitively expensive for most users.

Therefore, for those who just need a capacious network storage, the best option for home are special network storage systems - NAS (Network Attached Storage).

What is NAS

Above, we have already defined this device - it is a network storage system. Let's see what it is in practice.

Essentially, a NAS is a simple computer that is housed in a compact (if possible) case, equipped with an array of multiple hard drives, and connected to a home computer network. Classic NAS is designed exclusively for long-term and reliable storage of a variety of information and providing access to it from anywhere on the home network.

Since it is not designed to perform any computational tasks or direct user interaction, in the vast majority of cases, a keyboard, mouse and monitor are not connected to the NAS. The whole process of interaction with the storage takes place through the network, including its initial configuration. As a rule, this setting takes place through the web interface.

Typical NAS appearance

NAS software can be based on any of the well-known operating systems, but the most commonly used operating systems are the Unix family, FreeBSD, various Linux versions - due to their low (or absent) cost, flexibility, scalability and ease of administration. Since the configuration and interaction with the NAS takes place through the web interface, the OS installed in the storage does not play any role for the user.

When choosing a NAS, you need to estimate in advance your needs for the amount of network storage and take into account the following parameters: the number of hard disks installed at the same time in the system (can vary from two to eight), the ability to create RAID arrays from these disks and their type (necessary to ensure data safety if one disk fails), the bandwidth of the network protocol (now, as a rule, all NAS have a gigabit connection), additional functionality.

As an optional feature, many NAS provide software support for IP video surveillance systems. It is also often possible to configure access rights to stored information separately for each user.

It is important to be able to quickly create backups of all data with the click of a button. It is not uncommon for modern NAS to be equipped with software that turns it into torrent clients.

Another frequently requested function is the ability to provide remote access to information stored in the NAS. If configured correctly, you get access to the storage from anywhere in the world, wherever an Internet connection is possible. In fact, you can organize your own cloud storage.

Therefore, when choosing a NAS as your home storage, think in advance what tasks it will perform in your home, and choose a specific device based on your own requirements for its functionality.

NAS in practice

After reading the above, many enthusiasts probably asked themselves the question: if the NAS is an ordinary computer designed to perform a certain task, then can it be possible to assemble it yourself from the components available on the market? The answer is simple: of course it is possible. And home-made NASs are often found on the home networks of computer professionals. However, the economic gain today is not so great as to abandon ready-made solutions that are offered by almost all manufacturers of computer and network equipment.

So, who should you pay attention to in the NAS market, so as not to regret the money spent later?

NAS systems are currently in the assortment of computer giants such as IBM, Dell, Intel, Fujitsu, Asus, Iomega, Seagate, Western Digital, Sun Microsystems, Transcend, Kingston, ZyXEL, D-Link and most of the lesser known brands.

The devices they offer differ in the number of installed hard drives, design, operating system, functionality and, of course, cost.

Using the example of several specific devices, we will consider the variety of existing options.

Seagate Central

The simplest NAS, designed to install one hard drive with a volume of 2-4 TB. The main task is to provide access to data within the home network and remote access from the Internet. In fact, it is an external hard drive equipped with a network interface in addition to USB. It does not provide any additional services.

One of the major advantages of Seagate Central is mobility - like a regular external hard drive, it can easily fit into a small bag and can travel with the owner if necessary.

The cost ranges from 5-7 thousand rubles, depending on the volume of the installed hard drive.

D-Link DNS-315

Another representative of single-disk drives. The delivery set does not include a hard drive, the choice of hard drive is at the discretion of the user. Has quite advanced software for an entry-level model. Easily configured as an FTP server, it can function as a print server by connecting to a wide range of printers with a USB cable.

The gigabit network card provides fast data exchange with all members of the home network. It can store credentials with individual settings for 512 users at once, which allows it to be used as an exchanger in small offices.

The cost is about 1750 rubles.

Iomega ix2 35551

Network attached storage designed to install two hard drives up to 4 TB each. A gigabit network card, the ability to quickly back up data, an interesting design, small size and quiet operation make it attractive to a wide range of users.

The Iomega ix2 35551 can be purchased at a price of 9,900 rubles. At the same time, the initial package includes two disks of 2 TB each.

This is a professional drive designed for the simultaneous installation of up to eight hard drives. Arrays from RAID0 to RAID10 with hot-swappable drives are available. Support for all existing network protocols, two gigabit Ethernet channels, support for IP video surveillance systems, GSM monitoring, 4096 account management and many other functions that cannot even be listed in a short overview, make this device an excellent choice for organizing network storage a large office or large household with a developed video surveillance system and a large number of participants in the home network.

This system runs on an Intel Core i3-2120 processor clocked at 3.3 GHz, which interacts with 2 GB of RAM.

The cost of this device already exceeds 100 thousand rubles.

Short conclusion

Despite its short history, NAS systems are gaining popularity in small offices and home networks. Wide functionality, reliability of data storage, the ability to provide access to information in 24 × 7 mode, low power consumption and relatively low cost make them indispensable in the face of a rapidly growing demand for an increase in the amount of stored information.

As a cheaper replacement for full-fledged server solutions, NAS often does not yield to them in terms of the level of service provided, especially in small home networks and in the increasingly popular smart home systems.

Network-attached storage (NAS) is of great practical value for the comfortable use of your multimedia devices on your home network and organizing your media library: you can store various data (music, videos, documents, and much more) on it and access them whenever you want. You can use your data not only on a computer, but also play multimedia from a TV that supports and other devices connected to your home network (smartphones, tablets, laptops), as well as via the Internet using a client program.

How many hard drives should the NAS use?

The abbreviation NAS stands for, which in translation means - network data storage. Devices of this type connect to your home network, allowing you to access data from all devices. The use of 2 or more drives allows you to reliably protect yourself from data loss in the event of a HDD failure. To do this, the storage must operate in RAID 1. Thus, you do not have to worry about the safety of your photos and music collection, but you will have to sacrifice a decent amount of disk space. Two drive bays in a NAS is a reasonable minimum for home use. Based on the number of hard drives available, the Create NAS Arrays Wizard will only offer available options.

Installing and configuring network storage

When choosing the right NAS, you will find that they often come bundled with hard drives. But there are exceptions, for example, models from QNAP and Synology - in this case, you will have to buy and install at least 2 HDDs yourself. The initial setup of the NAS is performed in the supplied software or through the web interface accessible from a browser. As a bonus, the storage package includes a program that allows automatic backups. Of course, you can use alternative scheduled backup applications as well.

How do NAS devices differ from each other?

The main components of a NAS are the processor and network controller, which determine the speed of copying and transferring data over the network. From my own experience, I want to say that the highest operating speed is demonstrated by devices from Netgear, Buffalo, Thecus and Synology. When used at home, it will also be important to provide for noise from NAS devices. NAS, like conventional hard drives, differ in noise levels. For example, models from Synology and QNAP run almost silently, which cannot be said about some models from Buffalo and Thecus. Since NAS devices typically operate around the clock, power consumption is an important consideration when purchasing such a device. If you place a deep emphasis on this parameter, then make sure that there is a storage standby function. The devices are also easy to operate. For example, remote access to data sometimes causes difficulties for inexperienced users: for beginners with setting up this function, the D-Link NAS is famous for its problems.

Key features of network attached storage (NAS)

PLAYBACK... Today's TVs, Blu-ray players, game consoles, and other network-enabled devices support streaming multimedia content on your home network. Most modern network storages have the necessary built-in media server for this. When you activate the Media Server or DLNA Server function in the NAS settings, you can play music, display photos and videos on other network-connected devices such as a Smart TV. In this case, the transmission of both audio and video data is carried out in streaming mode, which eliminates the need to copy files to the corresponding playback device.

RIGHTS. The data stored on the NAS can be accessed from any device connected to the network. However, if necessary, you can, and sometimes need to restrict or, on the contrary, provide access to individual folders for certain users. In the process of creating a new account, the NAS administration panel allows you to assign access rights to existing directories, set quotas for the used disk space, select protocols with which a new user can access the storage, as well as set access speed limits for each of these protocols ...

REMOTE ACCESS. You no longer need to upload photos to a smartphone or tablet: almost every NAS model is accessible via the Internet, which allows you to offload the memory of mobile devices without losing access to content.

SAFETY. The NAS allows you to automatically back up data on your computer's hard drive. This greatly reduces the risk of losing important information in the event of a disk failure or PC theft.

These tips are less focused on providing some practical skills, and more on getting you acquainted with the functionality of NAS devices, learning about their capabilities before buying and weighing the pros and cons.

1. Connecting the printer to the NAS

Many network storage devices have a USB port to which you can connect a printer. This will allow you to print photos and documents from all network devices (for example, from a laptop, computer, tablet or smartphone) without installing drivers. I recommend taking a look at the list of printer model compatibility on the official website of the NAS manufacturer.

2. Remote access

Almost all NAS have free apps that allow you to remotely access multimedia data or, for example, upload vacation photos to your NAS, wherever you are. When connected to a LAN, NAS can receive IP parameters dynamically using DHCP, or be statically configured. The corresponding settings are available in the "Network" item in the control panel.

3. Copying data from a flash drive without using a PC

The presence of a USB port on the network storage allows you to take advantage of another useful function: documents, photos, videos and music stored on a USB flash drive or external hard drive can be easily copied to the drive without using a PC. Just insert the USB stick into the appropriate slot, if necessary, press the button and the data will be copied.

4. Music on your home network

Most NAS offers a practical feature such as the iTunes Music Server, allowing you to play music stored on your NAS on multiple devices on your home network at once - provided it's an Apple product such as an iPhone, iPad, Apple TV, or a computer with iTunes installed. ...

5. Data backup

All NAS have at least 2 bays for installing two drives, as this allows you to painlessly replace a failed hard drive in the future. In some models, they may even be installed. When using the RAID 0 mode, all drives in the NAS are detected by the computer as a single logical drive. However, in this case, the failure of any of them will inevitably lead to the loss of all data. Therefore, it is recommended to operate the storage in the RAID 1 mode (when using 2 HDDs). With this configuration, you can use only half of the drives for storing data, and use the other part to host the backup automatically created by the device. The advantage of this approach is the guaranteed safety of data in the event of a drive failure.

6. Sharing data

Network storages allow you to grant and block access to directories for certain groups of users, such as children. The corresponding settings can be found in the administrative panel of the drive. Select the "Users" item from the menu and create an account for each of them using the same names under which you log into the system. Set a password for each account. Go to the "Shared Folders" section and create several folders there - for example, one personal folder for each user, as well as one shared folder for multimedia files and documents. Each folder provides the ability to individually configure access rights. Users can access files stored on the drive by connecting the device as a network drive (Windows) or by double-clicking the NAS icon. To gain access, you must enter a username and password. As a result, all folders available to the user will automatically appear on the screen.

7. Increase the amount of memory

If desired, you can install larger hard drives in the storage. Most manufacturers take care of the maximum convenience of this operation: remove the panel, remove the drives, install new ones - you're done! Attention! Be sure to back up your data to an external hard drive ahead of time.

8. Installing applications

Synology NAS, QNAP and Netgear offer applications not only for smartphones and tablets, but also for PCs. They can be used to easily accomplish tasks such as sorting photos, limiting access to video files, cloud services, or performing backups.

9. Using DLNA

It is possible to play multimedia files stored on the NAS not only on a computer, but also on smart TVs, tablets and smartphones. To do this, in the NAS settings, you must activate data transfer using DLNA technology.

10. Changing the language

Some administrative panels of network storages are not Russified, so many users will be able to understand the intricacies of the settings only by connecting the appropriate language file (for example, D-Link or Thecus). You can find it on the manufacturer's website. Download it to your computer and click on the Language item in the NAS settings. Next, click on the Search button, specify the location to save the file and click on Apply. The file will be connected, after which the interface language will change to Russian.

Which RAID to Choose and How to Calculate Usable Capacity?

Disk Limits for Different RAID Configurations

• RAID0 (minimum 2 HDD)
• RAID1 (max 2 HDD)
• RAID5 (at least 3 HDD)
• RAID6 (at least 4 HDD)
• RAID5 + hot spare (at least 4 HDDs): option available only for RS40X and DS50X models

Formula for calculating the capacity of an NAS array

You can use the following formula to calculate the total storage array yourself:

• RAID0 = (z - System - Temp) * n
• RAID1 = (z - System - Temp) * (n / 2)
• RAID5 = (z - System - Temp) * (n-1)
• RAID6 = (z - System - Temp) * (n-2) (RAID5 + hot spare is calculated in the same way as RAID6, the additional HDD acts as a standby disk in case of failure).

Values ​​in the calculation formula:

• z= HDD capacity (e.g. 500GB, 1TB, etc.)
• n= number of HDD
• System= permanent system partition (2.3GB)
• Temp= temporary system partition (0.512GB)

Interaction of NAS and a device on the example of Android and iOS OS

As you already know, modern mobile devices (smartphones and tablets) successfully cope with many PC tasks related to information stored on a remote server. We cannot ignore the active development of mobile devices and the convenience of mobile access to content. NAS manufacturers are developing mobile applications that provide a comprehensive solution for managing and accessing NAS storage. You can also have access to the stored data from an alternative file manager: ES Explorer, Astro File Manager, etc. I will consider the model of interaction between Android and iOS devices using the example of a smartphone and a Synology NAS, as well as special applications available to implement this solution.

Mobile apps allow remote control of the NAS or access to the content stored on it through:

• local wireless network (Wi-Fi) within the same network segment with the NAS (for example, an Android smartphone and NAS are connected to the same router)
• Internet network, through access from 3G / 4G networks and public Wi-Fi networks

Let's take a look at Synology branded mobile apps:

• DS Mobile is a web-based version of the NAS operating system designed specifically for mobile devices.

• DS finder - an app for finding and monitoring Synology drives on your local network

• DS audio - an application for playing music stored on a storage device

• DS photo + is an application designed to access photos stored on PhotoStation.

• DS file - an application for accessing files stored on the drive
• DS cam is an application designed to view video from surveillance cameras that can be connected to Synology storage

All applications are free and available for download in the Android Market and AppStore.

Third Party Mobile Apps for Synology NAS

As I wrote above, alternative applications for interacting with the NAS from third-party developers are available for smartphones / tablets. Let's take a closer look at some of them.

UPnPlay- an application for working with media servers. Has the functionality of playing music, photos and videos. It is worth noting that UPnPlay allows you to play video with support for all language tracks and subtitles present in the file or in the same folder with it.

ConnectBot- application for working with SSH and Telnet protocols. It can be used to connect to any device that supports these protocols, including a Synology drive.

ES Explorer- an application developed to work with files, both on a local device and over the network. The application supports the SMB (Windows) and FTP protocols. Samba is more commonly used on a local network due to the ability to find other computers and NAS drives on the network. After the drive is found, you can connect to it by entering the login and password of one of the accounts. FTP, designed specifically for transferring files, is more commonly used when connecting over the Internet. In this case, you first need to enter the address of the drive and the login-password to access it.

P.S. I would be grateful if you point out topics that are worth considering in more detail. After all, it is not possible to write everything about NAS devices within the framework of one article.

11.01.2018 0 3768

Computing technology, be it a laptop or a computer, has long ceased to be exclusively a machine for work. Now, sophisticated computing technology is used mainly for the consumption of entertainment content, and therefore, the volumes of hard drives and the performance of equipment are constantly increasing. Every year, media content takes up more and more disk space. It is simply impossible to imagine a computer with a hard drive of less than 256 gigabytes, sometimes one collection of music can take up significantly more space, not to mention games and movies.

Thus, if in one apartment there are 2 - 3, and maybe more computers, you will have to spend a lot of money, not to mention offices where more than a hundred machines can work.

Using one hard disk in a local network To save on disk space, you can safely purchase computing equipment with a limited amount of space. In fact, 120 gigabytes will be enough to install the operating system, a set of useful applications and a couple of games.

For storing multimedia data, one computer is assembled, and in it, the main emphasis is on the volume of the hard disk.

The next step, a person connects computers into one local network, and opens access to the hard drive. Unfortunately, to access it, the computer must be in working order.

To combine computers into one local network, you can daisy chain them with a network cable. The disadvantage of this method is that for this you will have to purchase additional network cards, because if two computers are connected with a network cable, how to connect the third to them? This is especially difficult if a person uses a laptop. If you add up the money spent on network cards and patch cords, you will get a pretty solid amount, which is better spent on purchasing a Wi-Fi router.

Using a router, you can connect at least five computers using wires and even more thanks to wireless data transmission technologies. Indeed, if desired, not only laptops can work via Wi-Fi connection, but also stationary computers, for this you need to install a special card in the PCI slot or connect a USB Wi-Fi module.

Thus, all computers connected to the router will be in the same network environment.

The next step, a person opens access to the disk space of one of the computers, after which, his data can be used by any device located in the common network.

It is noteworthy that you can also access the hard drive using a mobile device, however, for this, the user will have to use a third-party application.

A hard disk connected via a local network does not work as an Internet resource or an FTP server; the connected disk space can be used as comfortably as a native hard disk. A person can easily open a video, view it by moving the slider along the timeline, open and edit graphic files, etc.

In other words, working with a mapped network drive is just as comfortable as working with local drives on your computer.

With the help of a connected network drive, if desired, you can even run installed video games, while, of course, it is necessary that additional software be installed on the user's PC itself.

Sharing setup

As an example, the Windows operating system is given, because this system is used by the overwhelming majority of users. To share your hard drive, you need to go to Control Panel and configure your network settings. To do this, go to the "Network and Sharing Center", then go to advanced settings (bottom item in the left menu) and enable sharing in all items of the current profile.

Now, you need to expand the "All networks" menu and go to the very end, where the user must switch the checkbox to "Disable sharing with password and protection".

When all the settings are entered, the person must save them and restart the computer.

After the above steps, the user opens access to the working directories of the current profile, in which, usually, no one buries anything. To open access to other folders, you need to create a directory on one of the local drives and in its properties go to the "Access" tab. Here, the person presses the "share" key and adds a new user "Everyone", after which, opens the ability to read and write for him. Now, any files moved to this directory will be available to all devices on the local network.

Mapping a network drive on other devices

Going to the "This computer" section, the user presses the RMB and selects "Add a new item", then, selects a network location and presses the "Browse" button. In the window that appears, you need to expand the network directory, select a computer with open network access and select the required folder.

Now, the shared directory will be permanently available in the "This computer" section. A person can both view the contents of the shared directory and modify it. Optionally, you can download the files directly to the network directory.

Summing up, it can be noted that to access the network directory from other operating systems, for example Android, you will have to use third-party applications, for example, ES Explorer or another file manager with LAN access.