diff --git a/centos/README.md b/centos/README.md index 227f53a4c..67f486273 100644 --- a/centos/README.md +++ b/centos/README.md @@ -37,6 +37,10 @@ Additionally, images with minor version tags that correspond to install media ar For example: `docker pull centos:5.11` or `docker pull centos:6.6` +## Overlayfs and yum + +Recent Docker versions support the [overlayfs](https://docs.docker.com/engine/userguide/storagedriver/overlayfs-driver/) backend, which is enabled by default on most distros supporting it from Docker 1.13 onwards. On Centos 6 and 7, **that backend requires yum-plugin-ovl to be installed and enabled**; while it is installed by default in recent centos images, make it sure you retain the `plugins=1` option in `/etc/yum.conf` if you update that file; otherwise, you may encounter errors related to rpmdb checksum failure - see [Docker ticket 10180](https://github.com/docker/docker/issues/10180) for more details. + # Package documentation By default, the CentOS containers are built using yum's `nodocs` option, which helps reduce the size of the image. If you install a package and discover files missing, please comment out the line `tsflags=nodocs` in `/etc/yum.conf` and reinstall your package.