The difference between raid10 and raid01 and the RAID level used by the server

RAID 10 and RAID 01 are two different RAID (redundant independent disk array) schemes. They have different disk layouts and data replication methods.

RAID 10 is a method of combining multiple hard disks into an array, where each hard disk is part of the mirror array. Specifically, RAID 10 uses at least four hard disks, divides them into two mirror arrays, and combines them into a striped array. This means that the data is divided into multiple stripes and spans all hard disks. Write on one set of mirror arrays while creating the same copy in the other group. If any hard disk fails, its corresponding image array can still access data, so data integrity is guaranteed, and RAID 10 provides higher read and write performance than a single image array.

In contrast, RAID 01 uses two sets of striped arrays. Each array consists of at least two hard disks, one for data storage and the other for backup. This means that RAID 01 requires fewer hard disks (at least four) than RAID 10, but it only provides the same read and write performance as one of the arrays, and cannot access the data in the backup array after failure, so the data integrity and availability are poor.

RAID 10 and RAID 01 are two different RAID levels, and their data distribution in the disk array is different. To determine which RAID level your system uses, follow these steps:

Run the following command to view the RAID levels in the current system:

 cat /proc/mdstat

If the displayed output contains the string "raid10", it indicates that your system is using RAID 10. If the displayed output contains the string "raid0+1" or "raid01", it indicates that your system is using RAID 01.

In addition, we can also physically check the hardware to determine the RAID level used. For RAID 10, at least four disk drives are required, and they will be divided into two groups in pairs. The disk drives in each group are set as mirrors. For RAID 01, at least four disk drives are required, and they will be divided into two groups in pairs. The disk drives in each group are striped.