free inventory management software
In asymmetric storage virtualisation - as is also the case for symmetric storage
virtualisation - advanced storage functions such as snapshots, mirroring or data
migration can be realised. The asymmetric model is, however, not so easy to realise as
the symmetric one, but performance bottlenecks as a result of an additional device in the
data path do not occur here. If we want to increase performance by the use of caching
for both application as well as metadata, this caching must be implemented locally on
every application server. The caching algorithm to be used becomes very complex since
it is a distributed environment, in which every agent holds its own cache (free inventory management software).
Data inconsistencies as a result of different cache contents for the same underlying
physical storage contents must be avoided and error situations prevented in which
an application crashes, that still has data in the cache. Therefore, additional mechanisms
are necessary to guarantee the consistency of the distributed cache. Alternatively,
the installation of a dedicated cache server in the storage network that devotes itself
exclusively to the caching of the data flow would also be possible. Unfortunately, such
products are not currently (2009) available on the market.
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