Software-defined storage

Finding an ap­pro­pri­ate storage model for a company, is often much more difficult than one thinks. Aspects such as ac­quis­i­tion costs, the security package on offer or the ad­min­is­trat­ive effort as­so­ci­ated with a dedicated solution play an important role in making a choice. As an al­tern­at­ive to a file server or popular solutions such as NAS (Network Attached Storage) or a storage-area network, the so-called software-defined storage (SDS) has come to the fore. What exactly this storage concept is, you’ll learn in the following article.

Software-defined storage is a storage ar­chi­tec­ture for computer systems in which the storage man­age­ment software is separated from the basic hardware. With a structure that’s based on the concept of vir­tu­al­isa­tion, a SDS storage en­vir­on­ment for this purpose relies on a universal interface for accessing storage resources, rendering specific software for the ad­min­is­tra­tion of in­di­vidu­al storage devices un­ne­ces­sary. In this way, the entire storage capacity of the different hardware com­pon­ents can be centrally bundled and scaled in any dimension, or dis­sem­in­ated to the accessing clients. This makes the entire storage ar­chi­tec­ture more flexible and cost-effective. With the help of software-defined storage, software can also define specific guidelines for managing the storage, as the following aspects show:

• Data de­du­plic­a­tion: Iden­ti­fic­a­tion and elim­in­a­tion of un­ne­ces­sary data copying
• Rep­lic­a­tion: Multiple storage and syn­chron­isa­tion of the same file
• Thin pro­vi­sion­ing: “Lean” storage al­loc­a­tion, where only the storage that is actually needed is reserved
• Snapshots: Virtual data maps
• Backups: Solutions for data backup

In the meantime, SDS as a storage solution for SMB and en­ter­prises is now offered by numerous providers, which is why the concrete im­ple­ment­a­tion of the concept often looks very different. At the same time, many providers are happy to offer software-defined storage as sub­com­pon­ents of software-defined data centers, in other words, vir­tu­al­ised data centre resources.

In order to achieve this in­de­pend­ence from the device man­u­fac­tur­ers and device types, SDS storage solutions rely on an ab­strac­tion layer between the physical storage and the data inquiry accessing it. Full control over this in­ter­me­di­ate layer is subject to the re­spect­ive provider, who can thus regulate how and where new data is stored. Users of a software-defined storage solution, in turn, receive a com­pat­ible SDS ap­plic­a­tion from the re­spect­ive provider, which can be used to regulate the separate memory re­quire­ments. If more space is required for the storage of data, for example, the ca­pa­cit­ies can be adjusted upward at any time – analogous to this, one can reduce the storage space that is available if the resources are no longer required.

Software-defined shortage offers numerous ad­vant­ages when compared with tra­di­tion­al storage solutions such as the NAS (Network Attached Storage) or SAN (Storage Area Network) ar­chi­tec­tures mentioned above. First and foremost, is the great flex­ib­il­ity that ac­com­pan­ies the cutting-edge concept of vir­tu­al­isa­tion. There is no de­pend­ence on the hardware and software of a specific man­u­fac­turer, nor is there a spe­cific­a­tion for the structure of the basic storage media. For this reason, the exchange of defective or outdated hardware is just as ef­fort­less as the ac­quis­i­tion of new equipment (x86-based storage is quite suf­fi­cient). Fur­ther­more, the following benefits speak in favour of the use of software-defined storage:

• High ef­fi­ciency: The hardware com­pon­ents in an SDS storage en­vir­on­ment operate as a single in­di­vidu­al, logical unit, and for this reason can be scaled ho­ri­zont­ally (is also referred to as “scale out”). As a result, the storage resources can be dis­trib­uted very ef­fi­ciently to the separate ap­plic­a­tions. Fur­ther­more, the capacity can be increased during operation.
• Easy con­nec­tion to different data sources: Re­gard­less of whether it’s complex storage area networks, external drives, HDD, SSD or flash memory media, virtual servers or cloud-based storage – with the software-based approach, the most diverse data sources can be merged into a uniform storage volume.
• Lower ad­min­is­trat­ive effort: As a software-defined storage en­vir­on­ment is set up, ad­min­is­trat­ors benefit from the high degree of auto­ma­tion. For this reason, the ad­min­is­trat­ive effort is limited.
• Increased security and avail­ab­il­ity: The in­de­pend­ence from dedicated hardware gives software-defined storage excellent pro­tec­tion from data loss due to defects in one or several storage com­pon­ents. For example, in case of a breakdown, another component can take the place of the storage network. This also includes optional security features such as data rep­lic­a­tion.
• Excellent scalab­il­ity: From the point of view of the user, software-defined storage is es­pe­cially worth­while due to the first-class scalab­il­ity of the storage resources that it uses. With the re­spect­ive software, storage can be logged into or scaled back in­de­pend­ently of time and location – whether it’s intended for one, several, or all connected ap­plic­a­tions.

With its demon­strated strengths, a software-based storage solution is suitable for the most diverse usage purposes. In this way, software-defined storage is, for example, an important part of hyper-converged systems, which are becoming more and more popular in answer to the modern chal­lenges of company IT. The IT package, which also comprises, among other things, the concept of software-defined net­work­ing, combines the ad­vant­ages of vir­tu­al­isa­tion and in-house hardware. In this way, it enables flexible resource man­age­ment and can also ensure high data security.

Some other possible areas of use for software-defined storage are the following:

• Big data analytics
• Con­nect­ing with cloud storage struc­tures
• Container man­age­ment
• Object storage
• Rich media storage