RAID

RAID

Redundant Array of Independent (or Inexpensive) Disks.

Ide awal: menggabungkan beberapa disk kecil yang murah menjadi satu disk besar

KELEBIHAN RAID

• Fault tolerance
• Persembahan yang lebih baik
• Ketersediaan data yang lebih baik
• Kapasiti yang lebih besar

RAID-5

RAID Level 5 is similar to level 4, but distributes parity among the drives. This can speed small writes in multiprocessing systems, since the parity disk does not become a bottleneck. Because parity data must be skipped on each drive during reads, however, the performance for reads tends to be considerably lower than a level 4 array. The cost per megabyte is the same as for level 4.

Level 5 - Block Interleaved Distributed Parity: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID.


BACKUP

Secara am, fungsi backup ataupun pendua membenarkan pengguna membuat salinan
sesuatu fail, program dan sistem operasi ke dalam media storan lain seperti cakera liut,
ruang storan cakera keras di server atau pita. Sebagai langkah keselamatan ketika
kerosakan fail, salinan fail yang telah dibuat boleh dikeluar dan digunakan semula