Chapter 2. Technology 43Figure 2-32 shows the typical FlashCache deployment scenario:Figure 2-32 IBM FlashCache Storage Accelerator deploymentThe FlashCache Storage Accelerator also works in virtualized environment, transparentlycaching data of virtual machines. Figure 2-33 shows the typical FlashCache deploymentscenario for virtual environment.Figure 2-33 BM FlashCache Storage Accelerator deployment in virtual environmentThe FlashCache Storage Accelerator software intelligently caches the most actively readapplication data. Cached data is read directly from flash cache instead of having to be readfrom the slower primary storage. If the data is not available in cache, FlashCache StorageAccelerator redirects the reads to primary storage and copies the data to cache to acceleratesubsequent reads.For write operations, FlashCache Storage Accelerator employs “write-through” caching wherewrites are written both to the FlashCache service in the host and to primary storage. A write isconsidered complete only when the write to primary storage is acknowledged. Subsequentreads of the data are quickly returned to the application from cache instead of from the slowerprimary storage.I/OinterfaceIBM SSDcacheDisksStorage protocolVolumes FilesPrimary data storagePhysical IBM serverOperating system (Windows Server or Linux Server)FlashCache Storage AcceleratorApplicationVMware vSphere ESXi hypervisorI/OinterfaceIBM SSDcacheVMDK datastore(VMDK file caching)Storage protocolVMDK datastore(Disks, Volumes, Files caching)Primary data storagePhysical IBM serverVirtual Machinewith guest OS (VMDK)FlashCache software(optional)ApplicationFlashCache Storage AcceleratorDisks Volumes FilesVirtual Machinewith guest OS (VMDK)FlashCache software(optional)ApplicationDisks Volumes Files
