Since large systems and servers need fast data access and a good backup strategy should things go wrong, RAID or Redundant Array of Independent Drives was developed to address this need. RAID is a technology that allows one to setup an array of multiple drives and have it recognized by the system as one logical drive. For example, if one has two hard drives, RAID can allow your system to see those two drives as a single drive. The advantages of this setup are improved performance for the combined drives for data access and data recovery in case of drive failure, depending on the RAID configuration.
RAID setup
RAID is setup in two ways: through a hardware RAID controller and through an adapter and RAID driver embedded onto the OS. Hardware RAID controllers are used for large server systems, while the adapter and driver is sufficient for personal and small systems that use the RAID configuration.
There are several RAID configurations, depending on the number of drives and the needs of a particular system. The most common are RAID 0, RAID 1, RAID 4, RAID 5, and RAID 10.
RAID 0, or striped or striping, is the basic RAID configuration. It requires at least two hard drives to setup. This configuration will take multiple drives and combine them into a single logical drive. Data are written in small blocks and are distributed equally among the drives, resulting in quicker data transfer. One can also enjoy larger storage space since all the drives are combined. The disadvantage is if one drive becomes defective, all data are lost.
RAID 1, or mirroring, is a configuration mostly for data security. It also requires at least two drives, wherein one drive is used for backup. What happens is that the same information is written in both drives, so if one drive fails, the data are safe on the other. This means that the combined disk storage is divided into two, since one of the drives is used only for backup. One disadvantage of this setup is slower data access, as information is written twice and the storage space of one drive is not utilized for data processing.
RAID 4 is an improvement on RAID 1 and as it combines the storage space of the hard drives and still leaves disk space for redundancy and backup purposes. It does this by using one of the drives as a backup, and the information is preserved through parity calculation. Even if one drive fails, the information is still safe and accessible. The disadvantage is that the parity calculation can cause latency on data access.
RAID 5 is similar to RAID 4. The main difference is that RAID 5 equally distributes the backup load on all the drives. It has the same advantages and disadvantages as RAID 4, only that RAID 5 shows quicker performance for data processing.
RAID 10 is a combination if RAID 1 and 0. It combines the multiple drives into one for faster data access, while also allowing data backup through mirroring on half of the drives.
Knowing which RAID configuration to use would depend on the needs of a system or network. For most home users, RAID 1 and RAID 0 are sufficient to cover most needs. RAID configurations can get more complicated for larger organizations and systems as data access speed and security is essential for those systems.
RAID setup
RAID is setup in two ways: through a hardware RAID controller and through an adapter and RAID driver embedded onto the OS. Hardware RAID controllers are used for large server systems, while the adapter and driver is sufficient for personal and small systems that use the RAID configuration.
There are several RAID configurations, depending on the number of drives and the needs of a particular system. The most common are RAID 0, RAID 1, RAID 4, RAID 5, and RAID 10.
RAID 0, or striped or striping, is the basic RAID configuration. It requires at least two hard drives to setup. This configuration will take multiple drives and combine them into a single logical drive. Data are written in small blocks and are distributed equally among the drives, resulting in quicker data transfer. One can also enjoy larger storage space since all the drives are combined. The disadvantage is if one drive becomes defective, all data are lost.
RAID 1, or mirroring, is a configuration mostly for data security. It also requires at least two drives, wherein one drive is used for backup. What happens is that the same information is written in both drives, so if one drive fails, the data are safe on the other. This means that the combined disk storage is divided into two, since one of the drives is used only for backup. One disadvantage of this setup is slower data access, as information is written twice and the storage space of one drive is not utilized for data processing.
RAID 4 is an improvement on RAID 1 and as it combines the storage space of the hard drives and still leaves disk space for redundancy and backup purposes. It does this by using one of the drives as a backup, and the information is preserved through parity calculation. Even if one drive fails, the information is still safe and accessible. The disadvantage is that the parity calculation can cause latency on data access.
RAID 5 is similar to RAID 4. The main difference is that RAID 5 equally distributes the backup load on all the drives. It has the same advantages and disadvantages as RAID 4, only that RAID 5 shows quicker performance for data processing.
RAID 10 is a combination if RAID 1 and 0. It combines the multiple drives into one for faster data access, while also allowing data backup through mirroring on half of the drives.
Knowing which RAID configuration to use would depend on the needs of a system or network. For most home users, RAID 1 and RAID 0 are sufficient to cover most needs. RAID configurations can get more complicated for larger organizations and systems as data access speed and security is essential for those systems.
