What is the disk read performance after all data has been pulled to local?

[Bubbleioa]

For example, I want to know these:

[lihuiba]

According to what you have provided, it seems that you are interested in read throughput of downloaded images. In fact we have developed a kernel module for best performance in this case. It is bounded primarily by the speed of SSD. Below is our test result:

In this figure, "DADIx" stands for the kernel module of overlaybd and zfile, and the image blobs are stored directly on a raw partition of SSD. Note that there is an ext4 file system made in the image.

And "EXT4" in the figure stands for an ext4 file system on a partition of SSD.

This module will be opened and contributed to upstream soon.