RAID or Redundant Array of Independent Disks enables the same data to be saved across multiple disks, yet appearing as a single logical drive.
NAS or Network Attached Storage is a centralised device accessible over a network using an ethernet connection, often employing ‘Just a Bunch of Disks’ or JBOD technology. The intrinsic redundancy built into RAID means that when a single disk fails, data can still be served, albeit in a ‘degraded’ state. JBOD on the other hand doesn’t have any redundancy. A three x 2TB disk setup will offer 6TB capacity with JBOD. However is a single disk fails, the data on that disk is lost.
Where RAID and NAS overlap
To provide data protection enterprise-grade NAS devices often employ a limited number of RAID configurations. NAS even offers hot-swappable devices, whereby a failed drive can be removed and replaced with a healthy disk. The RAID controller will automatically restore the array.
Either RAID or NAS
These are totally separate technologies and it need not be either/or, but both. If shared access is required, NAS is the sensible solution. RAID is optional, depending on your backup solution and performance/capacity requirements. RAID also works in workstations or DAS (direct attached storage) or SAN (storage area network) arrays.
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