This change implements the use of tmpfs for Cinder's image conversion
and encryption processes. Key improvements include:
- Performs image conversion and encryption in memory using tmpfs
(use from root disk to memory of /var/lib/cinder/conversion volume)
- Reduces IO load on the cinder Docker volume
- Enhances performance for large (virtual size) images
- Improves efficiency of image format conversion and encryption
This optimization is effective when sufficient memory is available on
the cinder-volume host.
Closes-Bug: #2089345
Change-Id: Idea788fdf12f0ae51041b368802b7c958952a847
a0c35ec1c8