Fault tolerance doesn't have to cut your storage space in half. Unfortunately, with the RAIDs (redundant array of independent disks) supported by many motherboards, such as RAIDs 1 and 0+1, that's exactly what happens. RAIDs 1 and 0+1 only leave you with 50% of your hard drives' capacity, thanks to their 1:1 mirroring of your data.
There's another option besides giving up data redundancy for RAID 0's 100% capacity. If you're willing to spend a couple hundred dollars on a controller card, you can build a fault-tolerant, relatively fast RAID that provides 66% or even 75% usable space. It's called RAID 5.
Instead of mirroring data, RAID 5 stores parity (error-checking) information. If there's an error or bit corruption, the parity data should catch it, and the RAID controller should correct it. All data and ECC (Error-Correcting Code) are striped over three or more hard drives, which speeds up reads and writes.
Parity data takes up less space than mirrored data, so a RAID 5 can yield a total capacity of the sum of its drives, less one
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Perso je préfère 100 fois le software au hardware oui, pour plusieurs raisons :
- tu mixes les partitions comme tu veux (raid0, raid1, raid5, etc), sans même avoir besoin de rebooter
- tu peux surveiller l'état des disques via SMART
- le support OVH a moins de chance de tout t'exploser en cas de changement de disque
Mais de ce que j'ai lu sur de vieux benchs, le mode software aurait une latence un peu plus élevée.
