Exinda EXNV-10063, Руководство администратора

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Exinda Network Orchestrator 4 Settings | 493
appliance is effectively sending the reads to the server and pre-populating both the client side and server side cache.
Since SMB1 clients perform reads serially, this dramatically improves cold pass read performance and helps to populate
the object cache quickly.
Write Behind
Writing behind the data stream is an optimization by which the Exinda Appliance immediately responds to the client
when it is trying to write a file. When the appliance detects a client attempting to perform a bulk write to a file, it
immediately responds to the client from the client side appliance. The end result is that the Exinda Appliance is
effectively sending the write requests to the server so the conversation between the client and client side appliance is
occurring at LAN speed. Since SMB1 clients perform writes serially, the immediate response by the appliance allows the
client write requests to fill the connection, making it appear to be asynchronous and significantly improving write
performance.
Meta-data Caching
Meta-data caching is an optimization by which the Exinda Appliance caches the properties related to files and folders
on both the client side and server side appliances. When a client queries the properties of a file or folder, it is served
from cache which eliminates the need to go across the WAN. This occurs quite frequently when browsing a file share
location that has a larger number of file and folder entries. Similar to the object cache, change notifications are registered
to ensure that the meta-data cache does not serve stale information.
SMB2
With the addition of SMB2, most of the optimizations that were implemented for SMB1 no longer apply. Below is a
rationale for each of these and why they are no longer needed.
Read Ahead and Write Behind
In SMB2, read ahead and write behind requests are built in to the client, effectively stacking the requests one on top of
the other in an asynchronous manner without any gaps between them. As a result, there is no accumulation of latency
and therefore no need for the appliance to attempt to perform any sort of read prefetching or immediate write
response.
Meta-data Caching
In SMB2, meta-data caching is performed by the client. This eliminates the need for the appliance to do any caching in
the middle as the client very quickly caches its own copy of the file and folder meta-data locally and uses that for the
duration of the session.
Compression and Deduplication
Aside from the protocol specific optimizations that are provided by the appliance, the Exinda SMB acceleration
framework also provides some significant downstream optimization benefits, primarily in the areas of compression and
deduplication. The SMB acceleration framework is reconstructing the SMB messages in their entirety before processing
them. This means that for large data centric operations like reading and writing a file, the appliance is actually operating
on large blocks of data as opposed to individual packets of fragmented data. In doing so, Exinda passes off these large
blocks of data to our WAN memory framework. This allows the WAN memory framework to heavily optimize for
compression and deduplication.
Accelerating Exchange and Outlook Traffic (MAPI)
Accelerate Exchange and Microsoft Outlook traffic
Exinda x800 appliances have built-in support for accelerating MAPI traffic. To gain the most benefits from Exinda's
acceleration, compression and WAN Memory technologies, it is recommended that any native encryption be disabled in