Multiple Read-Only Layers Added To OverlayFS Written by Michael Larabel in Linux Kernel on 11 February 2015 at 07:58 AM EST. 2 Comments OverlayFS was added to the Linux 3.18 kernel and for Linux 3.19 this file-system popular to live Linux distributions gained multi-layer support. For Linux 3.20 this file-system is now having support for multiple read-only layers. The OverlayFS changes were submitt