What are RAID and mdadm?

What are RAID and mdadm?

It's a way to use multiple hard drives together as if they were a single drive. It's used to speed things up or to prevent data loss if one drive fails.

On Ubuntu and Xubuntu, it's exactly the same. The only difference is the screen appearance. The mdadm tool works the same way on both.

1. The Idea of ​​RAID

RAID means: you put several disks together to form a team. The goal is to be faster or more secure.

2. RAID 0 - The Fast Mode

Files are split into chunks and distributed across all the disks.

The advantage: It's extremely fast.

The disadvantage: If a single disk fails, you lose EVERYTHING.

3. RAID 1 - The Secure Mode

An identical copy is made on two disks. It's like a mirror.

The advantage: If one drive fails, the other still has everything. You lose nothing.

The disadvantage: You lose half the storage space. If you have two 1TB drives, you'll only have 1TB of usable space.