Learning the ABCs for Network Storage - Part Two

SAN/NAS to English Dictionary

AFP - Appletalk File Protocol. As you might guess, the standard protocol for Apple's Appletalk networks.

CIFS - Common Internet Files System. A client/server application that allows mounting and accessing file systems on remote computers. CIFS is a public version of SMB (Server Message Block) developed by Microsoft. Your NAS server had better support this.

Ethernet - The standard networking connect technology and protocol. Developed by Xerox, DEC and Intel in 1976. 100Mbps is the speed of most current installations though older 10Mbps networks are still around and 1Gb is rapidly being deployed. 10 Gigabit is in the works.

Fabric - A fancy term to describe all the DAS/NAS/SAN storage and servers on your network. In other words, the whole kabob.

Fibre Channel - A storage communications standard and technology. Notice the spelling. Copper wire is used for runs of 20 meters or less and fiber optical for longer runs. Think FireWire or USB, but faster and with networking thrown in.

HBA - Host bus adapter. A card that plugs into your computer's PCI expansion slot and provides connection with external devices. For NAS, an Ethernet card, for SAN a Fibre Channel controller card.

Initiator - A server requesting information from a target. Most often a network server utilizing a SAN.

iSCSI - intelligent SCSI. A version of the SCSI protocol that can be used independent of the physical technology, mainly developed for use across Ethernet. Fibre Channel companies are investing in the technology, which should tell you something.

NAS - Network Attached Storage. Files servers that attach to your network the same way a workstation does--with an IP address-- and communicates via Ethernet and standard network protocols.

NCP - NetWare Core Protocol. The main protocol of Novell-based networks.

NFS - Network File System. Actually a client/server application that allows mounting and accessing file systems on remote computers. Pretty much the standard with UNIX. Your NAS server had better support this.

RAID - Redundant Array of Inexpensive Disks. A method for treating multiple physical disks as one logical disk to improve performance or using one set of disks to mirror the data on another for redundancy.

SAN - Storage Area Network. Literally a separate network devoted entirely to storage. Almost all SANs communicate and connect to your servers via a Fibre Channel host adapter card and switch.

Target - a storage device. Usually referring to storage boxes on a SAN.

Market-speak

Availability - the amount of time the stuff is online. See reliability.

Manageability - the quality of not eliciting blank stares from your best tech people

Redundancy - having two of everything.

Reliability - the quality of not breaking every time you really need it. See availability.

Scalability - the ability to be upgraded to match need. If a 1TB SAN can be upgraded to 9TB, it's scalable. How far is the question.

TCO - Total Cost of Ownership. Basically the price of the hardware and software, plus the money to operate it, plus the money you lose when it's not working.

Speed/Capacity

Gigabit - (Gb) one billion bits. There are 8 bits in a byte so 1 gigabit is approximately 125MB (megabytes)

Gigabyte - (GB) one billion bytes or 2^30, depending on the context.

Terabyte - 1000 Gigabytes or 2 ^ 40 depending on whose doing the talking.