> I sincerely hope no storage company acknowledges a write after just writing to volatile main memory. That's a recipe for disaster when a node goes down. Sorr

> I sincerely hope no storage company acknowledges a write after just writing to volatile main memory. That's a recipe for disaster when a node goes down. Sorry to break this to you, but this is exactly what every major storage product does. Data will be mirrored to separate DDR behind and then good status is given to the host. The data will be destaged at some point later when cache space is required for some other operation. The data itself is safe as long as the battery backup (or capacitor for smaller systems) is charged enough to handle a power outage. The storage system knows the battery levels and may not allow a write cache if there isn't enough supplemental power to destage the full write cache in the event of a power loss.