What are RAIDS
• RAID is an acronym meaning, Redundant
Array of Inexpensive Disks. It’s another way to
allow computer data storage.
• There are different levels of RAIDs, arranged
so that they are faster to write to and read
from than a single disk.
• RAID is not a good alternative to backing up
data, it may become damaged or erase
without you even knowing.
Types of RAIDS
• RAID 0 is simply data striped over several disks. This gives a performance
advantage, as it is possible to read parts of a file in parallel. However not
only is there no data protection, it is actually less reliable than a single
disk, as all the data is lost if a single disk in the array stripe fails.
RAID1 is data mirroring. Two copies of the data
are held on two physical disks, and the data is
always identical. RAID1 has a performance
advantage, as reads can come from either
disk, and is simple to implement. However, it is
expensive, as twice as many disks are needed
to store the data.
RAID4 data is written in blocks onto the data
disks (i.e. not striped), then parity is generated
and written to a dedicated parity disk.