如何在Redhat Linux 7现有Docker安装中切换为overlay2存储驱动

Let’s walk through the steps to switch your Docker storage driver to overlay2, which should resolve the checksum_type: too many links errors you’re facing with the legacy overlay driver.

Step 1: Stop the Docker service #

First, shut down Docker safely to avoid data corruption during the change:

sudo systemctl stop docker

Step 2: Back up your Docker data #

Always back up your existing Docker data before making configuration changes. Since your data is stored at /apps/var/lib/docker, run:

sudo cp -a /apps/var/lib/docker /apps/var/lib/docker.backup

This gives you a fallback if anything goes wrong during the switch.

Step 3: Update the /etc/sysconfig/docker file #

Open the configuration file in your preferred editor (e.g., vi or nano):

sudo vi /etc/sysconfig/docker

Locate your existing other_args line:

other_args="--insecure-registry ******* -g /apps/var/lib"

Add the --storage-driver=overlay2 flag to this line. The updated line should look like:

other_args="--insecure-registry ******* -g /apps/var/lib --storage-driver=overlay2"

Save and close the file once you’re done editing.

Step 4: Start Docker and verify the change #

Restart Docker to apply the new storage driver setting:

sudo systemctl start docker

Confirm the switch was successful by checking the active storage driver:

docker info | grep "Storage Driver"

You should see output like:

Storage Driver: overlay2

Key Notes #

• Overlay2 is fully supported on RHEL 7.4 (kernel version 3.10.0-693+ included with RHEL 7.4) as long as your filesystem supports d_type. For XFS (the default filesystem on RHEL 7), ensure it was formatted with ftype=1 (standard for RHEL 7.4 installations—verify with xfs_info /apps | grep ftype).
• If you encounter issues after switching, revert by stopping Docker, restoring your backup (sudo mv /apps/var/lib/docker.backup /apps/var/lib/docker), removing the --storage-driver flag from other_args, and restarting Docker.

内容的提问来源于stack exchange，提问作者Ashley