RAID Systems

The heart of every RAID system is the RAID controller. It is either built in as a hardware controller in the form of a board repectively micro chip, or as software controller. In terms of the latter, the functions of a hardware controller are being emulated. A RAID controller has various modes of operation that are called levels. They define the access method and the distribution of the stored data within the whole hard drive compound. Depending on the RAID level the focus of the system is on either the increase of the data transfer rate or on the increase of the security concerning hard drive failures. Certain forms of mixed RAID levels are capable of achieving both. Additionally many RAID systems provide the possibility of using the so called JBOD mode. At this, neither redundancy nor an increase in data transfer rate is achieved. This modes purpose is to make the system compound available as one single logical drive. This drives capacity is the sum of the single hard disc drives within the system.

There are different types of interfaces that are required to connect a RAID system to an already existing computer system. Besides a connection via SATA interface, which often can be found in private computers, a SCSI in form of SAS (Serial Attached SCSI) is more commonly being used. An interface that is mainly used for high speed data transfer in SAN networks (Storage Area Networks) is the so called Fiberchannel (FC). In order to provide a high flexibility despite the use of different kinds of interfaces, SAS and SATA hard disc drives can be operated within the same compound by using the EasyRaid and EonStor systems. This kind of flexibility makes sense especially when it comes to SAN networks.

If you have any questions regarding RAID systems and hard disc drives, feel free to contact us anytime: +49-7666-88499-0.