Fujitsu Siemens Computers CentricStor V3.1D, User Manual

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Glossary
Distribute and Activate
➟
DNA
Distributed Tape Volume File System
➟
DTVFS
DNA
The Distribute and Activate (DNA) function must be invoked in GXCC every time a
change is made to the configuration of the CentricStor system. This ensures that the
new configuration is distributed to and activated on all the
ISP s.
➟
section “Distribute and Activate” on page 188
DTVFS
DTVFS (Distributed Tape Volume File System) is a file system implementation which
was developed specially for CentricStor which has been adapted to the requirements of
high concurrence and of high-speed data traffic both between the
TVC (Tape Volume
Cache) and hosts and between the TVC and tape drives. In CentricStor V3.1D, all Tape
File Systems ( TFS s) of the TVC are of the type
dtvfs
.
Emulation
An emulation is a functional simulation of one system by another. The emulated system
receives the same data, executes the same programs and achieves the same results
as the original system.
Example:
A logical drive ( LD ) emulates a physical drive ( PD ).
Extented Tape Control Center
➟
XTCC
Failover
➟
AutoVLP failover function
FC
Fibre Channel (FC) is a standard which was designed for serial and continuous high-
speed transfer of large volumes of data. It is also used in the
Storage Area Network ( SAN )
within CentricStor and in some cases for the connections between the ICP s and the
hosts and between the IDP s and the back-end devices. The FC controllers used in
CentricStor support bandwidths of between 1 Gb/s (Gigabit per second) and 4 Gb/s.
In the case of a Fibre Channel, each device has a WWNN (World Wide Node Name)
and each port of a device a WWPN (World Wide Port Name) as a unique worldwide
identifier. Each of these is a 64-bit address which is generally presented in hexadecimal
format as 8 bytes separated by colons.
A distinction is made between three types of Fibre Channel topologies :
– Switched Fabric (FC-SW)
In the case of the
Fibre Channel Switched Fabric , point-to-point connections are
switched between the channel via one or more FC switches.
– Arbitrated Loop ( FC-AL)
In the case of the
Fibre Channel Arbitrated Loop a logical bus is involved on which all
terminals share the same bandwidth. In CentricStor, FC-AL can only be used to
connect back-end devices.
– Point-to-Point (FC-P2P)
This refers to a direct connection between two terminals.