How to choose the right SSD hosting for your applications

A disk subsystem has long been a "bottleneck" in both user computers and servers. Various tricks such as using the fastest disks with the speed of 15,000 rpm, RAID arrays, caching - could not significantly change the state of things, because the low speed was in the operation principle of the hard disk: mechanical reading heads could not work faster than a certain limit. Only solid-state drives (SSDs) were able to reverse the situation. Even the first models showed a significant increase in performance, in some cases, the difference could reach tens of times. So, it is not surprising that SSDs quickly took root in servers, especially in high-loaded ones.
But mainstreaming of solid-state drives quickly revealed problems that they did not bypass. First, the high cost of SSD drives significantly increased the total cost of renting equipment for end-users, so customers had a choice between an inexpensive and slow VPS with a hard disk or a fast but expensive server with an SSD. Also, over time, problems with reliability began to appear – the solid-state drive service life is less than the magnetic one so, to prevent data loss, it is necessary to make backups more often and replace worn-out equipment.
 

The SSD-HDD combination

 

A quite original solution was to combine solid-state and magnetic drives into one system: data is stored on large, but slow HDDs and requests are cached by fast, but smaller SSDs. In practice, this works like this: a request goes to a disk subsystem, content is checked first on an SSD disk, if it is not there, it is requested from the main storage, given to a client, and cached at the same time. This is similar to using a built-in cache memory, which is available on every hard disk, only it is not enough for any serious operations, and it does not work very efficiently. The main advantage of such a system is the rational use of the capabilities of both technologies – the speed of the SSD and large volumes of the HDD, without significant loss of performance. But when choosing this option, you need to understand that you will lose speed in any case, since a server with solid-state media will be faster.

Comparison of the SSD, HDD, and SSD caching speeds

 

Advertising promises that when you rent a server with caching on an SSD, you will get the same speed at a lower price and with more disk space. However, is this true? It all depends on how the server will be used. If it is a project with a large number of requests (a dynamic site, a 1C: Accounting database, a game server), the speed of work will be the highest on the SSD, the SSD-HDD combination will lose significantly, and magnetic disks, even industrial and the fastest (with the speed of 15,000 rpm) will be much slower. If you place on such a machine mainly data that will be requested relatively seldom (backups, archives, VPN), the speed of the solution with caching on the SSD can be similar to the SSD media. But even in this case, magnetic disks will be much slower. They should be used only in very small projects, where the speed of access does not play a fundamental role.

How the SSD caching is implemented in Linux

 

The SSD caching technology is very popular today because of a significant number of software solutions that allow its implementation. Since most servers run on Linux, there are a lot of programs designed for this system (although a popular WMware software supports this technology for Windows). The most popular solution is EnhanceIO – completely free and open source. The choice of this program is obvious: you can enable and disable caching "on-the-fly", without stopping the system. Moreover, an SSD can be dynamically assigned and reassigned as cache not only to a separate hard disk but even to its partition. Also, EnhanceIO is already included in the kernel, so there are no problems with installing and updating the package.

How to choose the right solution

 

Choosing between the SSD and caching on the SSD, you need to start, first of all, from the model of its use. If you need to host a static website with a small number of requests, a VPN, a database, backup storage, an archive, etc., a combination of the HDD (better combined in RAID arrays) with solid-state drives is ideal. It should be mentioned that the solution is suitable for those projects where only a small part of the data is frequently used, it will be in the cache, and the difference in performance will be almost imperceptible.

If you plan to host a dynamic website with high traffic, a web application, an online office with simultaneous access and teamwork, then you can not do without the SSD. The cache will not cope with a large amount of information, and failures in performance will be frequent. The most critical to the speed of data exchange are game servers, management accounting (for example, 1C), build servers, etc. - in short, wherever a large amount of information is transmitted and where a large number of requests are processed simultaneously.

Keep in mind that some providers, under the guise of pricing plans with SSDs, actually offer servers with solid-state disks only for data caching. Pay attention to the description of the disk subsystem, and if there is no detail in the description, check this question with the company's representatives before ordering.

 

Services with the SSD from Tucha

 

We provide our clients with only the best. TuchaFlex+ and TuchaBit+ cloud services, which offer high-performance VPS/VDS servers, are equipped with full-fledged high-speed SSD drives. In each of the offered services, you can choose either one of the existing tariff plans, or configure a personal plan that meets your requirements.

Maximum flexibility with consistently high performance – these are the advantages that you get when working with us. To make sure, read the reviews of satisfied clients and contact us in a convenient way for you to get a competent consultation.