Business Benefits of Network Attached Servers

For the most part, for shared storage needs, we highly recommend that small companies use NAS (Network Attached Storage) appliances to centralize the storage needs of their workgroups. NAS can be installed into an existing Ethernet network in a matter of minutes, and although its performance will be somewhat less than that of a SAN, the performance degradation won’t be noticeable to most clients. NAS performance is becoming very good, many engineers believe NAS performance is more than adequate for most file server applications, although you may not want to replace your FC or iSCSI SAN with NAS storage for heavily used database applications or e-mail servers. NAS SANs are less expensive than their Fibre Channel (FC), and even their iSCSI, cousins since there’s no need to purchase expensive FC Switches, FC Host Bus Adapters (FC HBAs) for the servers, or use more expensive fiber optic or Gbit ethernet cabling since 100Mb Ethernet is sufficient for NAS connectivity & standard ethernet switches & routers to provide the internetworking connectivity.

Storage Resources of Network Attached Servers

The storage resources of a NAS device are accessed via mapped network drives which talk to servers and clients through the NFS (network file system) or CIFS (common internet file system) protocols, run over the IP protocol. NAS communicates to client machines using TCP/IP Ethernet as the medium. NAS is a simple storage solution since no new networking infrastructure is needed to set it all. NAS can support Windows based clients using the CIFS protocol and Unix clients via NFS. Many NAS devices also support AppleTalk for legacy Macintosh clients. By implementing NAS SANs you can leverage both the TCP/IP network infrastructure and the knowledge & experience your network staff already has installing, operating, & maintaining Ethernet & TCP/IP networks. NAS is very simple to set up and maintain. The thin server technology used by most NAS devices is easy for network administrators of any skill level to understand and is very reliable. However, NAS is not a replacement for SANs. For one thing, as more NAS devices are added to a network, their sheer number can become a problem.

Accommodating Network Attached Servers

While some NAS devices have the ability to scale to several gigabytes in size, a well-designed Fibre Channel SAN can scale to accommodate terabytes worth of storage. As NAS use proliferates throughout a network, an IT manager has no option but to add more NAS units. Although an individual NAS device is easy to manage, it is extremely difficult to globally set parameters like security levels or application access to all NAS devices simultaneously throughout a corporate network, a crucial flaw that we wish NAS vendors would fix. NAS is a great solution to centralize files on a workgroup level, but for companies that want enterprise-wide storage resource centralization for their distributed systems, a SAN (iSCSI or FC) is the only viable answer.