Dell TL4000 User Guide - Page 48

The library allows the selection of the following Fibre channel port behaviors: v LN Port: (default setting) - an automatic configuration that tries arbitrated loop first, then switched fabric v L Port - arbitrated loop v N Port - point to point protocol in a switched fabric topology Cables and speeds Ultrium 3, Ultrium 4, Ultrium 5, and Ultrium 6 Fibre Channel tape drives use LC duplex fiber optics cables. The maximum distances that the library supports on a Fibre Channel link is determined by the link speed, the type of fiber (50-micron or 62.5-micron), and the device to which the library is attached. If the library attaches to an HBA (Host Bus adapter), refer to the distances that are supported by the HBA. If the library attaches to a switch, the supported distances are: v For a multi-mode 50-micron cable: - 1-Gbit link speed = up to 500 m (1640 ft) - 2-Gbit link speed = up to 300 m (984 ft) - 4-Gbit link speed = up to 175 m (574 ft) - 8-Gbit link speed = up to 150 m (492 ft) v For a multi-mode 62.5-micron cable: - 1-Gbit link speed = up to 300 m (984 ft) - 2-Gbit link speed = up to 90 m (295 ft) - 4-Gbit link speed = up to 50 m (164 ft) - 8-Gbit link speed = up to 21 m (68 ft) Note: Minimum distance for both 50 micron and 62.5 micron is 2 m (6 ft). The library uses 50-micron cables internally. Therefore, you must use a 50-micron cable to attach to the library's port. To attach to a 62.5-micron SAN, you must attach the 50-micron cable to an active port, such as a port on a switch. Zoning to isolate devices and enhance security For security reasons, it is important to limit the devices that a server or servers can recognize or access. Also, some performance configurations and SAN configurations result in a device seen multiple times from the same server. For example, if you have two HBAs from the same server that is connected to an Ultrium Tape Drive in the library, the drive is detected and displays as two logical devices. There are two special files for one physical device. Zoning addresses these issues. You can partition your SAN into logical groupings of devices so that each group is isolated from the other and can access only the devices in its own group with zoning. Two types of zoning exist: hardware zoning and software zoning. Hardware zoning is based on physical fabric port number. Software zoning is defined with a worldwide node name (WWNN) or worldwide port name (WWPN). While zoning can be reconfigured without causing an outage, some zoning configurations can become complicated. The advantage of the library's WWNN implementation is that you can avoid the exposure of introducing zoning errors because you do not have to change the zoning configuration if a drive needs service or replacement. 3-10 Dell PowerVault TL2000 Tape Library and TL4000 Tape Library User's Guide