How many hard drives do raid6 need?

raid6 requires at least 4 hard drives; raid6 is a private raid level standard proposed by some large companies. Its full name is "independent data disks with two independent distributed parity schemes", which means "with two Independent data disks for independent distributed verification schemes."

#The operating environment of this tutorial: Windows 10 system, Dell G3 computer.

How many hard drives are needed for raid6?

RAID-6 requires at least 4 hard drives.

raid 6 is a private RAID level standard proposed by some large enterprises. Its full name is "independent data disks with two independent distributed parity schemes. )". This RAID level is developed on the basis of RAID 5, so its working mode is similar to RAID 5. The difference is that RAID 5 writes the check code into a drive, while RAID 6 writes the check code into a drive. The code is written into two drives, which enhances the fault tolerance of the disk. At the same time, the number of disks allowed to fail in the RAID 6 array is only two, but the corresponding number of array disks is at least four.

RAID-6 is a RAID level that increases the parity information from one to two bits based on RAID-5.

Like RAID-5, RAID-6 stripes the logical disk and stores the data and parity bits, but adds a parity bit to each bit of data. In this way, when using RAID-6, two hard disks will be used to store parity bits, which enhances the fault tolerance function and will inevitably reduce the actual usage capacity of the hard disk. Previous RAID levels generally only allowed one hard disk to fail, but RAID-6 can allow two hard disks to fail. Therefore, RAID-6 requires at least 4 hard disks.

RAID6 technology is a RAID method designed to further enhance data protection based on RAID 5. It is actually an extended RAID 5 level. The difference from RAID 5 is that in addition to the same-level data XOR check area on each hard disk, there is also an XOR check area for each data block. Of course, the check data of the current disk data block cannot exist on the current disk but is stored in an interleaved manner. The specific form is shown in the figure. In this way, each data block has two verification protection barriers (one hierarchical verification and one overall verification), so the data redundancy performance of RAID 6 is quite good. However, due to the addition of a parity, the writing efficiency is worse than RAID 5, and the design of the control system is more complex. The second parity area also reduces the effective storage space.

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