What is the array card

A disk array is a system in which a number of hard disk drives are grouped together according to certain requirements, and the entire disk array is managed by an array controller. The full name of the array card is called the disk array card, which is used for RAID (cheap redundant disk array).

Redundant Array of Independent Disks (RAID) was introduced by the University of California at Berkeley in 1987. The original purpose of the development was to combine small and inexpensive disks to replace large expensive disks to reduce large quantities. The cost of data storage (the RAID is called the inexpensive Array of Inexpensive Disks), and it also hopes to use redundant information, so that when the disk fails, the access to the data will not be lost, thus developing a certain level. Data protection technology.

Working Principles and Features

The basic structural feature of RAID is Striping, which bundles two or more physical disks into groups to form a single logical disk. . Striping Set refers to bundling physical disk groups together. When leveraging multiple disk drives, the combination provides a better performance boost than a single physical disk drive.

Data is written to the combo in the form of chunks. The chunk size is a fixed value that was selected before the bundling process was implemented. The relationship between the block size and the size of the average I/O requirement determines the characteristics of the combined set. In general, the purpose of selecting block sizes is to maximize performance to accommodate different computing environments.

Array card type

The first type is the IDE array card. It used to be used in servers and workstations where data is important or has many hard disks. It can support RAID 0, 1. 0+1, 3, 5. It has basically been eliminated now.

The second type is SATA array card, which is mainly used in large-capacity data storage, Internet cafes, data security and other server areas. At the same time, some low-end cards also meet the needs of some home customers, and can support RAID 0, 1 , 0+1, 5, 6.

The third is the SCSI array card. It can be used on high-end workstations or servers to support many SCSI interface hard disks. Can support RAID 0, 1, 0+1, 3, 5 . This array card performance is very fast and of course the price is relatively high. However, it has basically been eliminated now.

The fourth is that SAS array cards are mainly used in some high-end workstations and servers. They have replaced the old SCSI interface and are compatible with SATA interface hard disks. They can support RAID 0, 1, 0+1, 5 , 50, 6, 60.

Advantages of Disk Arrays

Disk arrays have many advantages: first, increased storage capacity; secondly, multiple disk drives can work in parallel, increasing data transfer rates; providing checksum redundancy Increased data security...

RAID technology does provide higher performance metrics, data integrity, and data availability than typical disk storage, especially in today's I/O. With the bottleneck problem that lags behind CPU performance becoming more and more prominent, the RAID solution can effectively make up for this gap.