Although users can separate the space of SAN disk array through NAS gateway to read and write files, so as to realize multi-protocol support, this method is not economical, and users need to bear the additional construction and management costs of NAS gateway. Therefore, for users, the most important thing is to support multiple protocols on a single storage device at the same time, which has become the standard function of the mainstream unified storage system.
At present, the unified storage system needs to support FC, iSCSI, FCoE and other block protocols, as well as CIFS and NFS, the two most common file protocols. In addition, more and more unified storage has become more and more extensive in protocol support, and even some manufacturers have added support for object storage data in unified storage.
However, the support of unified storage for multi-protocol needs to be reflected in the management software eventually. If the management software can't be unified, it can't be truly unified even if it can support multiple protocols or interfaces at the hardware level. Looking around the storage systems of major manufacturers in the industry, some manufacturers' unified storage products are still integrating unified management software (some products still have two management software under a unified interface and switch to the corresponding management software through Link), but the unification of management software is bound to be the future trend and has become one of the necessary standards for unified storage.
Figure Hitachi Command Suite, the unified management platform of HUS, the unified storage product of HDS, can manage different types of data storage through the unified management platform. Thin provisioning is a technology that uses virtualization technology to reduce the deployment of physical storage in order to maximize the utilization of storage space. Its principle is very easy to understand. In order to ensure that the storage capacity of applications is sufficient, users usually deploy more applications than they actually need at that time. However, in the actual operation of the application, the deployed storage capacity may not be fully utilized. According to the actual use of users, the automatic thin configuration technology was born.
Figure 3: Comparison between thin configuration mode and traditional storage capacity configuration mode.
In fact, thin provisioning technology was once a "patent" for high-end storage systems. However, as more and more high-end storage functions move down, thin provisioning technology gradually appears in mid-range storage systems. As a substitute for the previous mid-range storage system, unified storage naturally integrates this technology.
Figure 4: Thin provisioning technology has become the standard configuration technology for unified storage.
Thin provisioning technology has become the standard configuration technology of unified storage, because server virtualization has gradually become popular, which has promoted the application of thin provisioning technology in the previous mid-range storage and the current unified storage. In server virtualization environment, each virtual machine has its own boot volume and data volume, and the capacity of the boot volume is determined by the operating system and boot software. By using thin provisioning technology, all kinds of data of virtual machines can be greatly reduced, thus saving a lot of storage space for users. In addition, the gradual popularization of SSD in storage system is also promoting the development of thin configuration. Solid-state disks do not have the problem of disk fragmentation, which makes thin provisioning technology easier to run on solid-state disks.
Figure 5: HP 3PAR's thin provisioning technology is a typical example of thin provisioning technology.
In addition to the block-based thin configuration technology, the file system-based thin configuration technology has also been widely concerned. In 2002, thin provisioning technology based on file system was introduced automatically, and most NAS vendors provided this function, including EMC, NetApp, HDS and Symantec. These products are equipped with thin provisioning technology based on file system, and users can automatically extend the file system after deploying this technology.
In fact, with the gradual popularization of unified storage, thin provisioning technology has undoubtedly become the standard configuration function of unified storage. With the increasing application of server virtualization and the rapid increase of unstructured data, thin provisioning technology will make unified storage more competitive and better meet the application needs of users. Since SSD was gradually incorporated into the storage system by storage manufacturers, many advantages of SSD have attracted the attention of users. The advantages of high speed, earthquake resistance and low energy consumption are the reasons why users flock to it. However, the high price of SSD is an obstacle for users to use it. In this context, automatic tiering technology came into being, which allows hot data to be stored on SSD and non-hot data to be stored on cheap storage media. It can be said that it is meaningless to add SSD to the storage system without automatic tiering technology.
Figure 6: Automatic tiering technology transfers random I/O to high-performance media (flash memory), reducing the I/O burden of mechanical disks, thus greatly improving the I/O performance of storage systems.
In fact, when automatic tiering technology was first introduced, it was also "exclusive" to high-end storage systems. Similar to thin provisioning technology, with more and more high-end storage functions migrating downwards, many mid-range storage systems have auto-tiering function, and now almost all mainstream unified storage products on the market have auto-tiering function, including EMC VNX series, IBM V7000 Unified, HDS HUS series, NetApp FAS series and so on.
At present, there are two main ways of automatic tiering technology in storage system. One is the automatic tiering technology based on migration, which can automate the process of data migration and automatically adjust the migration to the corresponding storage media according to the "cold" degree of data. Typical representative is the FAST VP technology of EMC VNX. The other is automatic tiering technology based on cache, which uses solid-state hard disk as cache, puts hot data into high-performance media, and saves copies on disk. The typical example is NetApp's flash cache technology.
Fig. FAST VP auto-tiering technology is used in EMC VNX FILE.
Figure 8: NetApp PAM technology (now renamed Flash Cache).
With the continuous improvement of technology of major manufacturers, many manufacturers can often provide users with automatic tiering technology based on caching and migration at the same time, so that users have more choices. Automatic tiering technology has become a standard function of unified storage. Compression or Deduplication Technology Due to the rise of Data Domain, this technology or concept has been widely recognized in the backup field. Users make full use of the concept of deduplication to reduce data storage space and improve storage utilization and disaster recovery efficiency. In fact, as early as a few years ago, when deduplication was the most popular, the industry was discussing the possibility of deduplication or compression technology entering the main storage. At that time, some manufacturers were already trying this possibility. With the passage of time, compression or deduplication technology has gradually become a function of the main storage system. Especially in today's virtual machine applications, a large number of virtual machines actually have a lot of duplicate data. Compressing these data will help improve the space utilization and storage efficiency of the storage system.
When it comes to deduplication or compression technology of storage system, we have to mention the A-SIS deduplication technology introduced by NetApp a long time ago. NetApp applies this technology to expired FAS products, and because it is integrated into its unified management system DataOntap, all FAS products can enjoy the benefits of this technology.
Fig. how NetApp FAS series deduplication works.
Figure10: the processing flow of netapp a-sis deduplication technology.
In addition to NetApp, other vendors have been working on primary storage deduplication or compression technology. Before the NAS platform, EMC had deduplication or compression technologies based on Avamar and RecoverPoint respectively. In order to make up for the deficiency of its unified storage VNX block-level deduplication technology, EMC added block-level deduplication technology to the RecoverPoint code base in the second half of 20 1 1. IBM has integrated Storwize STN, an online real-time compression technology, into its unified storage platform, V7000 Unified, which enables users to optimize data when initially creating data and compress data when writing data to disk. Dell also plans to integrate its compression technology Ocarina into its unified storage platform.
It can be predicted that compression or deduplication technology has attracted the attention of most manufacturers, and has gradually become one of the standard configurations of unified storage. Good compression or deduplication technology can improve the efficiency of unified storage platform.