Data ONTAP

In computer storage, NetApp filer, known also as NetApp Fabric-Attached Storage (FAS), or NetApp's network attached storage (NAS) device is NetApp's offering in the area of storage systems. A FAS functions in an enterprise-class storage area network (SAN) as well as as a networked storage appliance; for this reason they are colloquially referred to as "toasters". It can serve storage over a network using file-based protocols such as NFS, SMB, FTP, TFTP, and HTTP. Filers can also serve data over block-based protocols such as Fibre Channel (FC), Fibre Channel over Ethernet (FCoE) and iSCSI. NetApp Filers implement their physical storage in large disk arrays.

Most other large-storage filers from other vendors tend to use commodity computers with an operating system such as Microsoft Windows Server, VxWorks or tuned Linux. NetApp filers use highly customized hardware and the proprietary Data ONTAP operating system, both originally designed by NetApp founders David Hitz and James Lau specifically for storage-serving purposes. Data ONTAP is NetApp's internal operating system, specially optimised for storage functions at high and low level. It boots from FreeBSD as a stand-alone kernel-space module and uses some functions of FreeBSD (command interpreter and drivers stack, for example).

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