[MESOS-7580] Use root fs as lower RO layer and container fs as upper layer

• Type: Wish
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: containerization
• Assignee: Unassigned
• Reporter: Mikhail Lesyk
• Created: 27/May/17 12:19
• Updated: 30/Jul/19 07:16

Description

See example:

mkdir -p rootfs/{opt,container,workdir,result}
mount -t overlay -o lowerdir=rootfs,upperdir=rootfs/container,workdir=rootfs/workdir none rootfs/result
touch rootfs/result/opt/trash
umount rootfs/result
ls -a rootfs/opt/
.  ..

Where rootfs - imaginary root filesystem
rootfs/opt - variable directory on that filesystem
rootfs/container - container work dir
rootfs/result - result overlayfs mountpoint(root fs from container point of view)

So, any change under rootfs/result will be not visible from rootfs point of view and it will remain clean, so every container could have own snapshot of host's root filesystem, but changes would be individual.

Issue Links

• relates to: MESOS-9900 Include overlayfs upperdir in disk quota accounting.