Configuring NFS-server
Assumptions To collect sufficient and accurate information to create NFS server
configuration should answer the following questions : Is the intense pressure on
the attributes or intensive data? Will customers to use a caching file system
to reduce demand? How many average will be fully active clients? What types
of client systems to be used and under what operating systems they work? How
big file systems to be used in the separation of access? Repeat if demands of
different customers to the same file (for example, to include files), or they
belong to different files? What are the number and type of alleged exploitation
networks? Is the current network configuration suitable for the type of traffic?
Is the purported server configuration of the CPU to manage traffic associated
with the applicable network? If local network (WAN), whether the medium and
routers rather small delay and higher bandwidth to ensure the practicality of
NFS? Is the disk drives and SCSI host adapters to the main set of productivity?
Is the use of software tools like Online : DiskSuit to adequately burden on
access to records of all the disk drives? If used frequently writes NFS, does
the configuration of NVSIMM? Does the proposed strategy backup type, number
and location of the SCSI bus devices backup? Perhaps the most important
requirement for NFS-servera configuration is sufficient bandwidth and
preparedness network. This practice leads to the need for a configuration with
the number and type of networks and interfaces. As noted earlier, the most
important factor in determining the choice of network configuration, is the
dominant type of NFS used applications. For applications with intense pressure
on the required relatively few networks, but those networks must have high
bandwidth, such as FDDI network or CDDI. These requirements may be met with a
100baseT networks (Ethernet 100 Mbit / s) or ATM (Asynchronous Transfer Mode 155
Mbps). Most of the attributes intensive applications and working with a less
expensive infrastructure, but may require a large number of networks. To decide
on the choice of network is relatively easy. If for individual customer needs
aggregated speed in excess of 1 MB / s, or for simultaneous operation of
multiple customers need network bandwidth in excess of 1 MB / s, these
applications require high-speed networks. There are in fact (1 Mb / s)
artificially inflated, because it describes the speed that you do not exceed the
guarantee. Usually considered more prudent speed Ethernet network of
approximately 440 MB / s, but not limited to 1 MB / s. (Typically, users
perceive Ethernet as neotvechayuschuyu "is about 35% in network load. The figure
is 440 MB / s corresponds to 35% tax load lines with a capacity of 1.25 MB / s).
If you do the customary mode does not require bandwidth, it may be less than
adequate speed network environment like Ethernet or TokenRing. This environment
provides sufficient speed in the performance of lookup and getattr that dominate
annex intensive attributes and the relatively easy data traffic associated with
such use. High-speed networks are most useful for large groups of customers with
intense pressure on the rather because of the lower cost of infrastructure,
rather than for reasons of maximum capacity, in collaboration with one of the
other. This is the current state of NFS protocol, which is currently working
with blocks of length 8 MB and provides pre-selected only 8 MB (ie one operation
to the server can be defined as 16 MB of data). The overall effect of such an
organization is that the maximum data transfer speed between the client and
server to interact via FDDI ring is approximately 2.7 MB / s. (This speed is
achieved by using the file / etc / system on the customer operator set nfs :
nfs_async_threads = 16. Customers must run SunOS 4.1.x 12 biod demons, and not
eight as it is by default). The speed of three times the maximum speed, which
provides Ethernet though the speed of FDDI ten times greater. (NFS is an
application layer protocol (level 7 in the OSI model). Minutes lower levels,
such as TCP and UDP can handle much higher speeds, using the same hardware. Most
of the time waiting for responses and other processing application layer. Other
application layer protocols, not designed for immediate response and / or
confirmation, also can convey a much higher rate environment). Peak speed in the
case of 16 Mbps Token Ring is approximately 1.4 MB / s. More recently announced
a new version of NFS protocol +, which eliminates this limitation, allowing work
with much larger units. NFS + allows transmission blocks almost arbitrary size.
The client and server agree on the maximum amount for each unit to mount a file
system. The block size can grow up to 4 GB. The main advantage 100-Mbitnyh
networks using conventional versions of NFS is that the network can support many
simultaneous transmission of data without degradation. When the server sends the
data to Ethernet clients at the rate of 1 MB / s, the transmission consumes 100%
available network bandwidth. Attempts to transfer to the network more data lead
to a lower capacity for all users. The same client and the server can send data
at a speed of 2.7 MB / sec for FDDI rings, but in a high-speed network that
transaction consumes only 21% of available bandwidth. The network can support
five or six channel at the same time without serious degradation. This situation
can be likened to a high-speed backbone. When the traffic light (light traffic)
speed highway with two lanes and a speed limit of 90 kilometres per hour is
almost as good as vosmipolosnaya superhighway with a speed limit of 120 km per
hour. But when traffic is heavy (heavy traffic) Mainline much less susceptible
to congestion. The FDDI also slightly (about 5%) is more effective than Ethernet
and Token Ring environments in intensive sending data because it can put the
package more useful data (4500 bytes, compared to 1500 bytes to 2048 bytes
Ethernet and Token Ring to). When sending data of 8 MB needs to process only two
sets, compared with five or six for Token Ring and Ethernet. But all these
considerations are valid only for the environment with intensive data transfer,
as the attributes in the processing of requests is small (for 80-128 bytes), to
transfer only one package regardless of the type of network in use. If the
existing wiring in the enterprise network pre-empt the use of FDDI fiber, there
are standards for copper wire FDDI (CDDI), which ensures that switching network
with the existing facility on the basis of TP cable. While ATM has not yet
become a widely used technology, perhaps in the future it will become the main
vehicle for protection from intense sending data because it provides faster data
(currently defined data transmission speed 155 Mbits / s, 622 Mbit / s and 2.4
Gbit / s) and the use of point-to-point topology, in which each joint klient-hab
can work with a speed of its environment.
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