Owner`s manual

PlatinumNAS Owner’s Manual

TCP/IP (Transmission Control Protocol/Internet Protocol) A pair of communications

protocols that implement the protocol stack on which the Internet and most commercial

networks run. TCP is a peer-to-peer connection oriented protocol that guarantees the delivery

of data packets in the correct sequence between two peers. IP is the protocol that defines and

governs addressing, fragmentation, reassembly and time-to-live parameters for packets.

Windows Internet Naming Service (WINS) is Microsoft’s implementation of NetBIOS

Name Server (NBNS) on Windows, a name server and service for NetBIOS computer

names. Effectively, it is to NetBIOS names what DNS is to domain names - a central store

for information, However the stores of information have always been automatically (e.g. at

workstation boot) dynamically updated so that when a client needs to contact a computer

on the network it can get its update normally DHCP allocated address. Networks normally

have more than one WINS server and each WINS server should be in push pull replication,

the favoured replication model is the HUB and SPOKE, and thus the WINS design is not

central but distributed, each WINS server holds a full copy of every other related WINS system

records. There is no hierarchy in WINS (unlike DNS) but like DNS its database can be queried

for the address to contact rather than broadcasting a request for which address to contact.

The system therefore reduces broadcast traffic on the network, however replication traffic can

add to WAN / LAN traffic.

Write-back Cache When a cache is operating in write-back mode, data written into the cache

is not immediately written out to its destination in secondary storage unless the heuristics

governing the flushing of dirty data demands otherwise. This methodology can improve the

efficiency of write operations under favorable circumstances. However, its use can potentially

lead to incoherencies in a system that is not protected from power fluctuations or failures.

Write-through Cache When a cache is operating in write-through mode, data written into the

cache is also written to the destination secondary storage devices. Essentially write completion

does not occur until the data is written to secondary storage. Thus the contents of the cache

and the secondary storage are always consistent. The advantage is that the possibility of data

corruption is greatly reduced. The disadvantage is that write-through operations are more time

consuming

D-Glossary