: the server hard disk interface, to a certain extent, determines the technology of product structure, transmission performance, etc.Do you know what types server hard disk interface?Server hard disk interface include SATA interface, SCSI interface, 4 kinds of SAS interface, optical interface.How to choose the server hard drive?Server hard disk, and what is the difference between ordinary hard disk?Below small make up will introduce for you.What's server hard disk server hard disk 】 【
interface type Server hard disk, and the difference between ordinary hard disk
server hard disk and the difference between ordinary hard disk
enterprise application environment in general is unlikely to your DIY data center server, is purchasing HP, lenovo and so on name-brand computer more, so you can get better pre-sale technical support.However, in order to meet the needs of the growing enterprise network application performance, and often need to increase the number of new server, or by improving the existing server configuration to improve the overall performance of the server, the server hard disk but also influence the overall performance is important one annulus.
we say server hard disk upgrade, of course, have to find the right the performance bottlenecks in the server, such as upgrading the server hard disk may be considering the network I/O capacity, can also be based on want to use a new hard disk interface types, to improve the storage extension performance of whole machine, etc.Anyway, the server hard disk interface, to a certain extent determines the technology of product structure, transmission performance, etc.Therefore, we need to discuss, the server hard disk interface how to choose the right questions.What are
server hard disk interface type
a SATA interface, the scenery is still
SATA interface and called "Serial interface ", so now the SATA interface of hard disk is called a serial port is used to the hard disk.It is an evolution after the IDE hard disk.SATA physical design based on fibre channel as a blueprint, so the four core cable.SATA interface development up to now there are mainly three kinds of specifications, which is currently widely used SATA - 2 specifications, the transmission speed can reach 3 gb/s, as shown in figure 1 for a certain brand SSD with SATA - 2 interface specification.Now there are
SATA - 3 interface, as shown is the data in the west a SATA - 3 interface server hard disk.SATA - 3 interface in addition to the transmission rate increased to 6 gb/s, also provides read optimization Settings of various data types.For users, of course, the emergence of SATA - 3 interface does not mean that the existing SATA - 2 products will be eliminated, because although SATA - 3 adopted new INCITS ATA8 - ACS standard, but can still be compatible with the old SATA equipment.
as a result of the SATA interface server hard disk, very mature technology and construction cost is not high, so relative to other interface types of products, its market price is relatively common.Trust for business users budget is not high, in the original server architecture to upgrade the same interface but greater SATA interface - 2 hard disk capacity, is the best choice.
SCSI interface application more popularity of SCSI interface server hard disk is now most of the adoption of a server, it has the characteristics of data throughput, low CPU occupancy: used to connect the SCSI interface on the hard disk SCSI controller has an equivalent to the function of the CPU control chip, can replace the CPU processing most of the work;Now widespread adoption of Ultra hard disk 320 standard SCSI interface, data transfer rate of up to 320 MB/SEC.SCSI interface server hard disk and SCSI controller as shown.
moreover, SCSI hard disk with the support of the hot drawing technology of SCA2 interface, also very suitable for deployment in the team and departmental servers now.SCSI hard drives must be through the SCSI interface to use, and now the server motherboard integrates the SCSI interface commonly, also can install specialized SCSI interface card to connect more SCSI device, so its lateral extension ability is stronger.
so, SCSI interface server hard disk, the main is stronger than what aspects, and is suitable for what kind of enterprise environment?First of all, the SCSI disk redundant array (RAID) good support, can satisfy the enterprise environment of a large data storage, data security is guaranteed at the same time;Furthermore, SCSI hard disk rotational speed is already up to 15000 RPM, which makes the enterprise data center to guarantee the process performance;Once again, its low CPU usage and multitask parallel processing features, are available for growth companies environment provide a powerful data processing and storage support.Finally, from the as shown in figure 6 now, by contrast, the market price of the SCSI interface drives overall than SAS interface, but significantly higher than the SATA interface drive, so it is more suitable for assembly on security of data storage has certain requirements, capacity requirements, high processing performance requirements of enterprise environment.
three, seek to maximize performance of SAS interface
"SAS"Is the meaning of the serial connection SCSI, and simple to understand is the upgrading of SCSI interface technology improvement, the purpose is to further improve the performance of SCSI technology, availability, and scalable.Its characteristic is the disk devices can be connected at the same time more and more to save the internal space of the server;Such as SAS interface reduces the size of the cable, and with a finer cable collocation, and the specifications of the SAS hard disk is 2.5 inches, as shown in figure 7 is the Seagate (Savvio 15 k. 2) 2.5 in SAS hard disk interface.
better space makes the interface of hard disk can be widely deployed in the blade server.In the height of 2 u use eight 2.5 inches of SAS hard disk has become the choice of most of the OEM server vendors.In addition, the budget is not high cannot replace the existing server business, also can use SAS and SATA hard disk coexistence upgrades, SAS interface compatibility good down makes enterprise users they can be used in different applications.SATA hard disk can be used for general transactional processing, for example, while SAS hard disk can focus on the large amount of data and data availability is extremely critical applications.As shown for the hundreds of millions of information (annually) of ST - 1042 SAS - extraction D7 hard disk box, it's perfectly mixed support SAS and SATA hard disk, and can be worn with SAS or SATA hard drive control CARDS to support RAID 0, 1, 5 disk array pattern.
compared to the same capacity of Ultra 320 SCSI hard drives, SAS hard drives some more expensive, the main reason for its better extensibility, the tolerance of the compatibility and more reliable.And from the point of view from the server market, the main server vendors at home and abroad have been rushed out by SAS hard disk model, only the specific application and market status of product is different.In departmental applications such as positioning HP ProLiant DL380 G5, suitable for streaming media service and the IBM System of electronic commerce x3650 M2 etc, provide the full support of SAS hard disk.
four, application of high-end optical fiber interface
Fibre Channel (FC, Fibre Channel) is a kind of in order to improve the speed and flexibility more hard disk storage systems to the development of interface, it can greatly improve the communication speed of hard disk.For a large ERP system, or online real-time trading system needs more in terms of throughput, faster response speed of application environment, this kind of interface server hard disk is the best choice.Its product price, of course, nature also is more higher than the previous.
to sum up, different interface technology of server hard disk also determines their respective applicable conditions.Separate existence of SATA hard disk server products now does not see more, mostly for the portal application server tower.And SCSI and SAS, because has the CPU utilization rate is low, the connection is much many characteristics, such as performance is superior to SATA interface on the hard disk, so it can be the enterprise data center and application environments, such as the security server deployment.So far, the hard drive or server products on the market, also present two forms: mostly Ultra320 SCSI and SAS/SATA.
there is no denying that, in 2009, SAS has become main drive platform server field, there has been a recent corporate users of server hard disk upgrade requirements, or more likely to choose SAS platform as well, although its price is significantly higher, but the actual application effect is better.Server where your hard disk drivers and the general difference between
first, HDD for Server and HDD for PC is not the same, of course, Server usually use SCSI interface hard disk (SAS have now replaced the SCSI), generally USES the ATA interface and PC hard disk (SATA has replaced the ATA) now, SCSI hard drives, has the advantage of the system takes up a very small, such as dozens of GB of data will you D disc copy to E plate, at the same time dozens of GB of data from disk copy to E D disk, disk resources should be the basic consumption net, again at the same time run CS, if on a PC, this can take up two copying all of the CPU resources, CS could not run, but on the Server, these two copying almost does not use any CPU resources, CS, besides just in slightly slow once read into memory, can be a very smooth running normally.
compared to ordinary PC hard drive, server to use the hard drive has the following four characteristics.
server USES the hard disk rotational speed is fast, can achieve 7200 or 10000 revolutions per minute, or even higher;It also configured with a large (generally is 2 MB and 4 MB) back to the write cache;The average access time is shorter;External transfer rate and internal transfer rate is higher, the use of Ultra Wide SCSI, Ultra2 Wide SCSI, Ultra160 SCSI, Ultra320 SCSI standard SCSI hard drives, data transfer rate respectively can reach 40 MB per second, 80 MB, 160 MB, 320 MB.Because the server hard disk is almost
2, high reliability,
working around the clock, under a lot of effort.Hard disk, as it were, if wrong, the consequence is unimaginable.So now, the hard disk S.M.A.R.T technology is adopted, the monitoring, analysis and reporting technology), at the same time hard disk vendors have adopted the advanced technology of their own to ensure data security.In order to avoid the unexpected costs, server hard disk are generally able to withstand the impact of the 300 g to 1000 g.More than
3, use the SCSI interface
most server adopted large data throughput, low CPU occupancy SCSI hard drives.SCSI hard drives must be through the SCSI interface to use, and some SCSI interface is integrated in the server motherboard, some with a dedicated SCSI interface card, a SCSI interface card can pick seven SCSI device, this is can't be matched by the IDE interface.
hotplug can support Hot plug (Hot Swap) are supported by the server hard disk installation, can be on the server without downtime, pull out or insert a disk, changes in the operating system automatically recognize the hard disk.The technology for 24 hours non-stop operation of the server, it is quite necessary.