Net App Filer

Net App Filer

In computer storage, NetApp filer, known also as NetApp Fabric-Attached Storage (FAS), or NetApp's network attached storage (NAS) device are NetApp's offering in the area of storage systems. A FAS functions in an enterprise-class storage area network (SAN) as well as a networked storage appliance. It can serve storage over a network using file-based protocols such as NFS, CIFS, 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 vendors' filers tend to use commodity computers with an operating system such as Microsoft Windows Storage Server or tuned Linux. NetApp filers use highly customized hardware and the proprietary Data ONTAP operating system, both originally designed by 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 is booted from FreeBSD as a stand-alone kernel-space module and use some functions of FreeBSD (command interpreter and drivers stack, for example).

All filers have battery-backed NVRAM, which allows them to commit writes to stable storage quickly, without waiting on disks. Early filers connected to external disk enclosures via SCSI, while modern models (as of 2009) use FC and SAS protocol. The disk enclosures (shelves) support FC hard disk drives, as well as parallel ATA, serial ATA and Serial attached SCSI.

Implementers often organize two filers in a high-availability cluster with a private high-speed link, either Fibre Channel, InfiniBand, or 10G Ethernet. One can additionally group such clusters together under a single namespace when running in the "cluster mode" of the Data ONTAP 8 operating system.