Applicable environment for various raid scenarios

[Data Recovery issues]

RAID has different organizational scenarios, there are JBOD,RAID0,RAID1,RAID5,RAID6,RAID10,RAID01,ADG, and so on, what are the scenarios that apply to the environment?

Answer

There are 3 major problems with raid to solve: capacity consolidation, IO performance, storage security

The JBOD is a low-end raid structure, sometimes the same as Windows spanned volume, is 1 or several hard drives connected to the end of the structure, only to solve the hard disk expansion problem, security header, IO performance and a single disk, suitable for the security level and IO performance is not high capacity combination environment. Can be made up of any number of hard drives.

RAID0 implementation of capacity consolidation, IO performance improvement, especially IO performance is the main feature of RAID0, but the security is very poor, than the single disk is also easy to damage, and the design cost is very low, suitable for fast IO, large capacity, but the data is not important environment. For example, the transit of the data server, streaming media on-demand system, or the requirements of the monitoring system is not high. Can be made up of any number of hard drives.

RAID1 Security Highlights storage security, providing the highest safety factor in all raid levels, and of course wasting space, increasing costs, while IO performance is not significantly improved, and is suitable for small, but extremely important, environments. It is usually only suitable for two disks.

RAID5 is a neutralizing RAID structure that provides large-capacity space, and if the controller is good enough to provide more than a single disk of IO performance (especially read performance), while providing security to allow a piece of hard disk damage, due to various factors are considered, so the use of a broader, The disadvantage is that the minimum required 3 hard disk components, at the same time RAID5 algorithm complex, the need for a strong processing unit and high-speed buffering to better play the role of RAID5, resulting in high costs. Low-end RAID5 may actually be more problematic and less performance than a single disk. Applies to most storage requirements for a generic enterprise. Multiple hard drives can be built.

RAID10 and RAID01 are a combination of RAID0 and RAID1 structure, usually recommended to do RAID10 (see Together with data disaster raid0+1 and raid1+0), the standard RAID10 suitable for more than 4 blocks of even block hard disk formation, security such as RAID1, Speed such as RAID0, but will waste 50% of disk space, processor design is simpler, large enterprise data storage, such as space requirements, RAID10 is preferred.

RAID6 and ADG are RAID5 upgrade structures, support two hard drives offline at the same time, making the security higher, but the algorithm is too complex, resulting in IO Read and write hit rate is very low, IO performance is very low, even with high-speed processor and high-speed buffering, still not necessarily the best organizational structure, the cost is very high, usually rarely used. But if a lot of hard disk, data volume is very large, RAID5 security level is not high enough, RAID10 and waste too much, RAID6 or ADG is the most suitable.

North Asia Data Recovery Center, http://www.datahf.net