Replies

RAID 5 is not a good choice if you are using multi-terabyte drives. RAID 5 can withstand a single drive failure. When a RAID 5 array is rebuilding, the drives are subject to very high I/O and mechanical stresses (spindled drives). Because of the extended rebuild times (1+ days) on multi-terabyte drives, a 2nd drive failure is highly probably. When this happens, all data is lost.

At my work we use RAID 1 when write performance isn’t a concern. Everything else is RAID 10. Of course, RAID 10 is too expensive for most home users….if their hardware even supports it. Assuming you have a good backup solution (3+ copies of your data that gets regularly backed up), RAID 1 is a perfectly viable disk redundancy solution.