Success Story: Upper cache congestion problems led to a performance collapse – solved in hours!
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In short Special circumstances can cause an overload of the SVC/Storwize upper cache. The impact of this situation can be very dramatic. In this example, the customer environment was near to a complete standstill. It is sometimes amazing how quickly small problems can develop into a complete fiasco .
The performance problem is very difficult to understand if it is an upper cache overflow, because the performance of VDisks are extremely bad while no effects can be seen in the partition caches or mdisks.
In this customer situation we could very quickly find the root causes of the bottleneck and initiate countermeasures which solved the problem in an instance!
A second BVQ scan some days later, proofed that the problem was solved permanently
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