Glossary · Automation fundamentals, platforms and components
RAID (redundant array of independent disks)
Also known as: RAID system, RAID array
German: RAID-Systeme
In IT and industrial computing, RAID (redundant array of independent disks) combines several drives into one logical unit to improve availability, performance or both, using striping, mirroring and parity. Common levels are RAID 0 (striping, no redundancy), RAID 1 (mirroring), RAID 5 and 6 (parity) and RAID 10.
- Automation components
In one sentence
RAID combines several disks into one logical drive to add availability or speed, using mirroring, striping or parity; it is not a backup.
Example
The SCADA server stores its historian on a RAID 1 array, so a single disk failure does not interrupt data recording.
How it applies
- Engineering: SCADA, historian and MES servers or industrial PCs use RAID to survive a disk failure. RAID 0 adds speed but no Redundancy; losing one disk loses all data.
- Maintenance: A failed disk puts the array into a Degraded mode; rebuild it promptly and monitor RAID status through diagnostics or alarms, otherwise a second failure loses data.
- Documentation: Service manuals should explain how to recognize a degraded array, how to replace a disk and which replacement drives are approved.
RAID vs. backup
RAID protects against disk hardware failure. It does not protect against deletion, ransomware, software errors or site damage, because every change is mirrored immediately. A separate, tested backup is still required.