【Newsletter#233】What to Do If a Hard Drive Installed in ASUSTOR NAS Fails?

[Crystal.Y@AST]

After a RAID array has been set up, data is typically not lost immediately in the event of a hard drive failure. ADM supports RAID 1, RAID 5, RAID 6, and RAID 10, all of which can support at least one hard drive failure. When a hard drive in a RAID array fails and you’re using a spare drive, ADM will automatically sync the data to the spare hard drive, replacing the failed one to ensure the volume continues to operate normally, avoiding a degraded volume. Note that RAID does not replace backups. You still need backups regardless of whether or not you use RAID.

Impact of Different RAID Levels:
• RAID 0: Improves read/write speed but does not offer any data protection. If any hard drive fails, all data is lost.
• RAID 1: Data is fully mirrored to another hard drive. If one drive fails, the system automatically recovers the data from the mirrored drive.
• RAID 5: Composed of three or more hard drives, it can tolerate one hard drive failure.
• RAID 6: Composed of four or more hard drives, it can tolerate two hard drive failures.
• RAID 10: Composed of four or more hard drives, it can tolerate multiple hard drive failures without data loss. RAID 10 mirrors data with RAID 1 and then splits the hard drives into two groups using RAID 0, combining performance and fault tolerance.