Shulou(Shulou.com)06/02 Report--

Server hardware and RAID configuration practical Server hardware detailed RAID disk Array detailed solution Array Card introduction and Real Machine configuration Construction of soft RAID disk Array 1. Server hardware detailed description RAID is the abbreviation of English Redundant Array of Independent Disks, Chinese abbreviation for independent redundant disk array RAID, right? multiple independent physical hard disks are combined in different ways to form a hard disk group (logical hard disk) Thus, it provides higher storage performance and data backup technology than a single hard disk. The different ways to form a disk array are the RAID sector (RAID Levels), and the commonly used RAID levels are as follows: RAID0 disk arrays such as RAID0,RAID1,RAID5RAID6,RAID1+0 introduce that RAID0 continuously divides data in bits or bytes and reads / writes in parallel on multiple disks, so it has a high data transfer rate, but it has no data redundancy, so it is not a true RAID structure RAID0 simply to improve performance. There is no guarantee for the reliability of the data, and the failure of one of the disks will affect all data RAID 0 can not be used in situations with high data security requirements.

Spanned volumes: LVM volum

Features: scalability

Composition conditions: disks of different sizes are appended

Capacity: total capacity of multiple disks

Striped volumes: striped volumes raid0

Features: highly written

Disadvantages: unreliable

Composition condition: composed of disks of the same size

Capacity: total capacity of multiple disks

Example:

Mdadm-D / dev/md0 view the details of the raid disk array

RAID 1 achieves data redundancy through disk data mirroring and produces split data on pairs of independent disks. When the original data is busy, it can read data directly from the mirror, so RAID 1 can improve read performance. RAID 1 has the highest unit cost in the disk array, but provides high data security and availability. When a disk fails, the system can automatically switch to the mirrored disk to read and write without the need to reorganize the failed data. Mirrored volumes: raid1

Features: high reliability

Disadvantages: lack of scalability

Composition condition: composed of disks of the same size

Capacity: half of the total capacity of multiple disks

Example:

-x1 means a spare disk

View the status, which is being synchronized at this time.

At this time, a disk is simulated to be broken to see if the disk in the standby state will be replaced.

Uninstalled

Successful replacement, synchronizing.

RAID 5N (N > = 3) block disk is composed of an array, one piece of data produces a stripe, colleagues also have a check data, a total of N pieces of data are cyclically balanced on N disk to read and write at the same time, the read performance is very high, but due to the problem of verification mechanism, the write performance is relatively low (NMU1) / N capacity reliability is high, allow bad 1 disk, does not affect all data Raid5

Features: high reading, general writing, high reliability

Composition: at least 3 disks of the same size

Capacity: sum of disk capacity of nmurl

Example

RAID 6N (N.V. 4) blocks form an array. Compared with RAID 5, RAID 6 adds a second independent parity information block.

Two independent parity systems use different algorithms, and even if the two disks fail, it will not affect the use of data with greater "write loss" than RAID 5, so the write performance is poor.

After pairwise mirror image of RAID 1 × 0N (even number, N > = 4) block disk, the N block disk has high read performance and high reliability after being combined into a RAID 0N/2 capacity Nbank disk and writing at the same time.

Next step is formatting

2. The array card is the card used to realize the RAID function, which is usually composed of a series of zero components, such as the Icano processor, the hard disk controller, the hard disk connector and the cache. Different raid cards support different RAID functions, such as the interface types of raid cards such as RAID0, RAID1, RAID5, RAID10, IDE interface, SCSI interface, SATA interface and SAS interface array cards. The cache cache is the place where raid cards exchange data with external buses. Raid cards first transfer familiar sentences to the cache. The size and speed of free cache and external data bus exchange data cache are important factors directly related to the actual transmission speed of raid cards. Different raid cards have different memory capacity when they leave the factory. Generally for a few megabytes to hundreds of megabytes of capacity this chapter summarizes the hardware composition of the server RAID provides higher storage performance than a single hard disk and provides data backup technology commonly used RAID level RAID0, RAID1, RAID5, RAID6, RAID1+0 and other array cards and cache

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