From 48e659e30c9d9704a9aad2bbbe6a7de50f656b91 Mon Sep 17 00:00:00 2001 From: Derek McGowan Date: Mon, 11 Jul 2016 16:48:08 -0700 Subject: [PATCH] Allow option to override kernel check in overlay2 Add option to skip kernel check for older kernels which have been patched to support multiple lower directories in overlayfs. Fixes #24023 Signed-off-by: Derek McGowan (github: dmcgowan) --- docs/reference/commandline/dockerd.md | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/docs/reference/commandline/dockerd.md b/docs/reference/commandline/dockerd.md index a881b62ac6..8c53fd02c3 100644 --- a/docs/reference/commandline/dockerd.md +++ b/docs/reference/commandline/dockerd.md @@ -566,6 +566,17 @@ options for `zfs` start with `zfs` and options for `btrfs` start with `btrfs`. Example use: $ docker daemon -s btrfs --storage-opt btrfs.min_space=10G +#### Overlay2 options + +* `overlay2.override_kernel_check` + + Overrides the Linux kernel version check allowing overlay2. Support for + specifying multiple lower directories needed by overlay2 was added to the + Linux kernel in 4.0.0. However some older kernel versions may be patched + to add multiple lower directory support for OverlayFS. This option should + only be used after verifying this support exists in the kernel. Applying + this option on a kernel without this support will cause failures on mount. + ## Docker runtime execution options The Docker daemon relies on a