RAID - kylessukaichang/kylessukaichang.github.io GitHub Wiki

RAID
- Just a Bunch Of Disks,JBOD
- RAID 0
  - Performance
- RAID 1
  - Redundant
- RAID 10(Redundant Array of Independent Disks Mode 10)
  - Performance + Redundant
- RAID 2
  - Most of what RAID 2 offers is now is available in modern hard disks as a standard like ECC, so there's no reason to use it.
- RAID 3
  - Techopedia Explains RAID 3
    - The disks must spin in sync
      - so sequential read/write (R/W) operations achieve good performance.
    - However, random R/W operations may take heavy hits in performance.
  - RAID-3 on the cheap -- is it possible?
    - Replied from Rob B. (Independent) Independent Advisor
      - Personally I think the Software and Hybrid are a waste of time and misleading when claims of reliability are usually made. In most cases an effective backup plan is better than these.
      - All too often the RAID software and/or Hybrid model actually cause a failure. Or what is supposed to protect the system in drive crashes and failures ends up being the cause of them.
      - Hardware RAID is by far the best.
- RAID 4
  - like RAID 3, but block level, not bit level.
- RAID 5
  - Performance + Redundant
  - one parity computation
  - to recover from one failed drives.
- RAID 6
  - Performance + Redundant
  - either two parity computations instead of one or it performs the same parity computation on overlapping subsets of the data.
  - to recover from two failed drives.