Server-Side Cache Solution
Price of the system is lower, because StarWind uses commodity hardware like conventional RAM, SATA SSD, MLC FLASH or so for caching. Expensive flash memory will have better lifetime because of possible SSD usage in either write-through or write-back mode, while StarWind uses conventional RAM as a write buffer and Level 1 cache to adsorb writes. This approach turns Flash into Level 2 cache, reducing the amount of write cycles going through it, prolonging its life. Additionally, space reduction technologies, namely in-line deduplication and compression, lower the actual amount of data to be written, allowing flash memory to last even longer, cutting the bills by requiring rare replacements.
StarWind raises performance by having bigger cache for the same money. Commodity inexpensive hardware is used – MLC flash instead of costly SLC flash, so more memory may be bought to meet workload requirements. In addition, starting VM’s after migration does not affect the performance as all moved VMs are started in “hot state” because caches are kept coherent – synchronized between nodes. This means that the destination node holds the required data in cache, so the VM starts without loss in performance.
Reliability is kept at maximum – StarWind basically mirrors data in cache between multiple nodes, creating distributed cache. This way, even when the power goes out, all data is safe, because redundant replicas are stored on all nodes. Besides, cache blocks are digitally signed, negating the possibility of silent data corruption – bit rot. Additionally, space reduction technologies lengthen the life of flash memory, lowering the risk of failure.
StarWind Cache Solution