A NAS uses your companies existing Ethernet network to allow access to shared disks. This is filesystem level access. The system administrator does not have the ability to partition or format the disks since they are potentially shared by multiple computers. This technology is commonly used to provide multiple workstations access to the same data.
Similar to a SAN, a NAS need to make use of a protocol to allow access to it's disks. With a NAS this is either CIFS/Samba , or NFS.
Traditionally CIFS was used with Microsoft Windows networks, and NFS was used with UNIX & Linux networks. However, with Samba, Linux machines can also make use of CIFS shares.
Does this mean that your Windows 2003 server or your Linux box are NAS servers because they provide access to shared drives over your network? Yes, they are. You could also purchase a NAS device from a number of manufacturers. These devices are specifically designed to provide high speed access to data.
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