add note to docs about overlay + btrfs

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Upstream-commit: 340ea25ac1c01561399175e4de8cecc2928ccf4b
Component: engine
This commit is contained in:
Jessica Frazelle
2014-12-10 14:29:41 -08:00
parent be5e940362
commit a9df8138c1
@@ -180,7 +180,10 @@ share executable memory between devices. Use `docker -d -s btrfs -g /mnt/btrfs_p
The `overlay` is a very fast union filesystem. It is now merged in the main
Linux kernel as of [3.18.0](https://lkml.org/lkml/2014/10/26/137).
Call `docker -d -s overlay` to use it.
Call `docker -d -s overlay` to use it.
> **Note:**
> It is currently unsupported on `btrfs` or any Copy on Write filesystem
> and should only be used over `ext4` partitions.
#### Storage driver options