Raid6最少要幾顆硬碟

RAID 6 is a type of RAID level that provides fault tolerance for up to two failed drives. It is typically used in situations where data redundancy is critical, and the cost of the drives can accommodate the overhead of the additional drives required for RAID 6.

To achieve RAID 6, you need at least four hard drives. With four drives, two drives can fail without losing data, as the data is spread across all four drives in a way that allows for the recovery of data from the remaining two drives.

Here's how RAID 6 works with four drives:

1. Data Striping: Data is striped across the drives, meaning that data is written across multiple drives.
2. Parity Striping: Parity information is striped across the drives. Parity information is used to reconstruct data if a drive fails. With RAID 6, two parity stripes are created, which allows for the recovery of data if two drives fail.

If a drive fails, the data can be reconstructed from the remaining drives. If a second drive fails, the data can still be recovered using the parity information, but it is important to replace the failed drives as soon as possible to prevent the loss of data.

In summary, RAID 6 requires a minimum of four hard drives to provide fault tolerance for up to two failed drives.