bootc-usr-overlay - Man Page

bootc usr-overlay [Options...]

Adds a transient overlayfs on /usr that will be discarded on reboot. The overlayfs is read/write by default.

A common pattern is wanting to use tracing/debugging tools, such as strace that may not be in the base image. A system package manager such as apt or dnf can apply changes into this transient overlay that will be discarded on reboot.

However, this command has no effect on /etc and /var - changes written there will persist. It is common for package installations to modify these directories.

Almost always, a system process will hold a reference to the open mount point. You can however invoke umount -l /usr to perform a "lazy unmount".

--read-only

Mount the overlayfs as read-only. A read-only overlayfs is useful since it may be remounted as read/write in a private mount namespace and written to while the mount point remains read-only to the rest of the system

v1.15.0