RAID


## redundant array of inexpensive disks

[Hardware RAID](https://texonom.com/hardware-raid-861083a0395649d18fa43e8b5dec9f51)


### RAID level - originally 5 level

[RAID 0](https://texonom.com/raid-0-5b52502a6406464689c2bf557f5d3b47)


[RAID 1](https://texonom.com/raid-1-b4b2a03a0193424e8fa40b4ee7488be7)


[RAID 2](https://texonom.com/raid-2-1b24579f29674f05a13c00b5075f2739)


[RAID 3 ](https://texonom.com/raid-3-4cc5f5d7b3c84145825a3f9bc4975ec9)


[RAID 4](https://texonom.com/raid-4-f4db629dc21d4e58a8ad908a83be049f)


[RAID 5](https://texonom.com/raid-5-afdf3a4add0a4374958c915fea1f83ef)


Usual tech of server and NAS and data center
### Two design goals of various RAIDs
1. increased data reliabilitymirroring data
2. increased input/output performance
trade-off between reliability and performance


> even parity, odd parity for detect block failure
> Striping : Disk striping - look at the diagrams which are like stripes





