whatis raid
RAID
Also known as: mdadm, software RAID, RAID 1, RAID 5
Combining multiple disks for redundancy, speed, or both. On Linux it is usually done in software with mdadm, ZFS, or Btrfs.
What Is RAID in Linux?
RAID 1 mirrors disks, RAID 0 stripes for speed with no redundancy, RAID 5 and 6 use parity to survive one or two failures, and RAID 10 stripes across mirrors. Linux mdadm builds these from any block devices.
RAID protects against a disk dying, not against deletion, ransomware, or corruption written by software. It does not replace backups.
Example
cat /proc/mdstatLearn more about RAID
- Software RAID with mdadm: Levels, Setup, and What RAID Does Not Do Linux software RAID is mature, fast, and free. Here is what each level actually gives you, how to build and monitor an array, and why RAID is not a backup.
- Hardware vs Software RAID Why the controller that was supposed to be faster is now usually the liability, what a BBU actually buys you, and where hardware RAID still wins.