When connecting an M.2 or SATA hard drive to the server, the division of labor between array cards and ordinary expansion cards is different. Before setting up a RAID, clarify three things to avoid most rework.

The expansion card is responsible for access, and the array card is responsible for organization.

An ordinary expansion card transparently transmits the PCIe channel to the disk slot, and the system can see the hard disk one by one in the device manager, and the partitioning and fault tolerance are all handled by the operating system; the array card has built-in RAID logic, which can combine multiple disks into one logical disk, supporting redundancy and reconstruction. When you need independent roles such as boot disk and cache disk, expansion cards are more flexible; when you need data security, you have to look at array cards.

Capacity and Risks of Common RAID Levels

  • RAID0 uses full capacity but has no redundancy. If any disk fails, the entire set of data will be damaged;
  • RAID1 has two disks with mutual backup, and the available capacity is half of the total capacity, which is suitable for small-capacity critical data;
  • RAID5 has at least three disks, and the available capacity is the sum of n-1 disks, taking into account both space and fault tolerance;
  • Performance drops significantly during reconstruction, and the reconstruction window for large-capacity disks is long. It is recommended to retain spare disks and enable alarms.

Implementation suggestions for mixing and selection

Small-scale M.2 and SATA hybrid disk, optionalPCI-EX4 to 2-port M.2+2-port SATA array card, complete mixing and formation in one card; when the demand for disk space is greater,PCI-EX8 to 4-port M.2+4-port SATA expansion cardIt provides higher density and is convenient for system-level storage space management.

Before placing an order, confirm three points: whether the target RAID level is in the card's support list, whether the disk protocol matches, and whether there is heat dissipation margin in the chassis. If necessary, you can contact EB-LINK technical support to check each item.