Performance Evaluation of RAM-based Caching Solution at Hypervisor and Storage Level for Network-Attached Storage on VMware Platform

The application of cache was an alternative solution to improve storage performance. Especially in a virtualization environment, storage performance was the top priority because of its performance impact on all of the running VMs. The implementation of the cache solution can be seen from a 3-layers perspective (3 layers: Storage, hypervisor and VM). The experimental tests conducted within this paper aimed to observe the characteristics of the performance gained from the implementation of RAM-based cache solution at layer 1 (storage level) and layer 2 (hypervisor) on NAS-based storage. Test results in write-back mode (cache for read and write operations) showed that layer 1 cache is superior for accelerating write-operation performance (up to 7,29 times), while layer 2 cache is superior for accelerating read-operation performance (up to 3,92 times). Continuing the test, the combination of layers 1 and 2 cache provides performance improvements up to 4,27 times for read operations, and up to 8,23 times for write operations, all were compared with baseline score (condition without cache).