EWF RAM Mode (Standard 7 SP1)

7/8/2014

EWF RAM mode uses the following configuration:

• The EWF Overlay type is stored in RAM.
• The EWF volume is stored on disk.

The EWF RAM overlay stores the write cache in RAM. When EWF RAM mode is configured during the EWF installer phase, the EWF volume is created in available space on media. The EWF volume stores the EWF master volume table and an overlay stack that points to the overlay data in system memory. When you shut down the target system, the overlay data in system memory is lost. EWF RAM mode supports only one overlay level.

Use EWF RAM mode in the following scenarios:

• Protecting data on a read/write volume from being altered or corrupted.
• Deploying a run-time image on a stateless device.
• Deploying a run-time image on a device without persistent read/write storage.

The following diagram shows an example EWF RAM mode configuration.

EWF RAM overlays require additional RAM to store the write cache. RAM is not pre-allocated by EWF. Therefore, EWF uses free RAM until the system runs out of memory. RAM requirements for the EWF RAM overlay vary. They depend on the amount of write operations that are made to the overlay. We recommend that, although you test your run-time image, you review the memory usage of your applications in Standard 7 Task Manager.

For more information, see Configure EWF RAM Mode.

See Also

Other Resources

EWF Modes