• /var/lib/container is moved to a different disk sda1.
• Ephemeral storage stays with /var/lib/kubelet
• This is achieved by crio creating the writable layer for containers on the first disk when configured with a separate disk for /var/lib/container, instead of under the default /var/lib/containers which is on the second disk.

• Only sda0 hosting /var/lib/kubelet is considered for disk usage accounting, capacity and eviction calculations
• Since rootfs and ephemeral storage are on sda0, that is okay.
• One problem here is the image GC will look at sda0 filling-up and try to clean-up sda1 in order to free-up space. Obviously, this will not work.
• Mitigation is to make it read-only ( no writable layer by default), so, writable layer is not used by accident.

Benefits 

1. Saving space on root by separating read only layer on sda1 it will free up space of images in sda0 (root)
2. I/O throttling : having multiple disk can improve I/O