diff --git a/install/linux/docker-ee/centos.md b/install/linux/docker-ee/centos.md index 784d2de031..d802d697a9 100644 --- a/install/linux/docker-ee/centos.md +++ b/install/linux/docker-ee/centos.md @@ -28,17 +28,27 @@ Docker CE users should go to ### OS requirements -To install Docker EE, you need a maintained version of CentOS 7. Archived -versions aren't supported or tested. +To install Docker EE, you need the 64-bit version of {{ linux-dist-long }} +running on `x86_64`. -The `centos-extras` repository must be enabled. This repository is enabled by -default, but if you have disabled it, you need to -[re-enable it](https://wiki.centos.org/AdditionalResources/Repositories){: target="_blank" class="_" }. +In addition, you must use the `overlay2` or `devicemapper` storage driver. +Beginning with Docker EE 17.06.2-ee-5 the `overlay2` storage driver is the +recommended storage driver. -In addition, you must use the `overlay2` or `devicemapper` storage driver if you -use Docker EE. On production systems using `devicemapper`, you must use -`direct-lvm` mode, which requires one or more dedicated block devices. Fast -storage such as solid-state media (SSD) is recommended. +The following limitations apply: + +**OverlayFS**: + +- The `overlay2` storage driver is only supported on CentOS 7 systems + using version 3.10.0-693 or high of the kernel. +- If `selinux` is enabled, the `overlay2` storage driver is only supported on + RHEL 7.4 or higher. + +**Devicemapper**: + +- On production systems using `devicemapper`, you must use `direct-lvm` mode, + which requires one or more dedicated block devices. Fast storage such as + solid-state media (SSD) is recommended. ### Uninstall old versions diff --git a/install/linux/docker-ee/rhel.md b/install/linux/docker-ee/rhel.md index 8e346715b2..a1e1930f5f 100644 --- a/install/linux/docker-ee/rhel.md +++ b/install/linux/docker-ee/rhel.md @@ -39,7 +39,8 @@ The following limitations apply: **OverlayFS**: -- The `overlay2` storage driver is only supported on RHEL 7.2 or higher. +- The `overlay2` storage driver is only supported on RHEL 7.2 or higher systems + using version 3.10.0-693 or high of the kernel. - If `selinux` is enabled, the `overlay2` storage driver is only supported on RHEL 7.4 or higher. diff --git a/storage/storagedriver/overlayfs-driver.md b/storage/storagedriver/overlayfs-driver.md index 82ed336564..6074c9ef38 100644 --- a/storage/storagedriver/overlayfs-driver.md +++ b/storage/storagedriver/overlayfs-driver.md @@ -15,7 +15,9 @@ storage driver as `overlay` or `overlay2`. > **Note**: If you use OverlayFS, use the `overlay2` driver rather than the > `overlay` driver, because it is more efficient in terms of inode utilization. -> To use the new driver, you need version 4.0 or higher of the Linux kernel. +> To use the new driver, you need version 4.0 or higher of the Linux kernel, +> unless you are a Docker EE user on RHEL or CentOS, in which case you need +> version 3.10.0-693 or higher of the kernel and to follow some extra steps. > > For more information about differences between `overlay` vs `overlay2`, refer > to [Select a storage driver](selectadriver.md#overlay-vs-overlay2). @@ -29,8 +31,11 @@ OverlayFS is supported if you meet the following prerequisites: - The `overlay` driver is allowed but not recommended for Docker CE. -- Version 4.0 or higher of the Linux kernel. If you use an older kernel, you - need to use the `overlay` driver, which is not recommended. +- Version 4.0 or higher of the Linux kernel, or RHEL or CentOS using + version 3.10.0-693 of the kernel or higher. Docker EE users using kernels older + than 4.0 need to follow some extra steps, outlined below. + If you use an older kernel, you need to use the `overlay` driver, which is not + recommended. - The following backing filesystems are supported: - `ext4` (RHEL 7.1 only) @@ -38,6 +43,13 @@ OverlayFS is supported if you meet the following prerequisites: `xfs_info` to verify that the `ftype` option is set to `1`. To format an `xfs` filesystem correctly, use the flag `-n ftype=1`. + > **Warning**: Running on XFS without d_type support inow canses Docker to + > skip the attempt to use the `overlay` or `overlay2` driver. Existing + > installs will continue to run, but produce an error. This is to allow + > users o migrate their data. In a future version, this will be a fatal + > error, which will prevent Docker from starting. + {:.warning} + - Changing the storage driver makes any containers you have already created inaccessible on the local system. Use `docker save` to save containers, and push existing images to Docker Hub or a private repository, so that you @@ -84,22 +96,27 @@ Before following this procedure, you must first meet all the } ``` + > **Note**: RHEL and CentOS users on Docker EE 17.06 + > + > You need to add a second option to the `daemon.json` to disable the check + > for version 4.0 or higher of the Linux kernel. Your `daemon.json` should + > look like the following. **This is only needed for Docker EE users of RHEL + > or CentOS.** Do not attempt to use `overlay2` with kernel versions older + > than 3.10.0-693. + > + > ```json + > { + > "storage-driver": "overlay2", + > "storage-opts": [ + > "overlay2.override_kernel_check=true" + > ] + > } + > ``` + If you need to use the legacy `overlay` driver, specify it instead. - To use `overlay2` on CentOS (Docker CE only), you must also set the storage - option `overlay2.override_kernel_check`. In this case the `daemon.json` - would look like this: - - ```json - { - "storage-driver": "overlay2", - "storage-opts": [ - "overlay2.override_kernel_check=true" - ] - } - ``` - - See all storage options for each storage driver: + More storage options are available. See all storage options for each storage + driver: - [Stable](/engine/reference/commandline/dockerd.md#storage-driver-options) - [Edge](/edge/engine/reference/commandline/dockerd.md#storage-driver-options)