Brief Introduction:
1, Docker 1.12.6/v17.03 documents in the CENTOS7 system installation, clearly stated that for production, must use the Devicemapper-driven DIRECT-LVM mode, we need to prepare the block equipment in advance to provide better stability and performance. The Devicemapper-driven LOOP-LVM mode is used by default because the installation is simple and applies only to test environments. As can be seen from the Docker info information, the maximum available space for LOOP-LVM mode is 107GB. The Devicemapper-driven DIRECT-LVM model must be used in a production environment, using block devices that are faster and use system resources more efficiently.
2, in Docker v17.06 and later versions, about OVERLAYFS storage drive, try to use overlay2 instead of overlay, the official note is overlay can be used but not recommended. When using Overlay2, the Linux system kernel requires more than 4.0, or the CentOS7 kernel is above 3.10.0-693. Docker-ce v17.06 and above, additional parameters need to be set when using the Overlay2 driver to prevent detection of the kernel as version 4.0.
official website screenshot:
01-docker v17.03 Document CENTOS7 system installation, it is clear that, for production, must use the Devicemapper-driven DIRECT-LVM mode, requires us to advance the block equipment, to provide better stability and performance
The Devicemapper-driven LOOP-LVM mode is used by default when installing CENTOS7 systems in 02-docker v17.03 documents, because the installation is simple and only applies to test environments
03-docker v17.03 document in the CENTOS7 system installation, the default use of the Devicemapper-driven LOOP-LVM mode, Docker info information shows that the maximum available space is only 107GB
04-The Devicemapper-driven DIRECT-LVM mode must be used in the production environment, with block devices, faster and more efficient use of system resources
05-about OVERLAYFS Storage drive, try to use overlay2 instead of overlay, when using Overlay2 Linux system kernel requires more than 4.0
06-new version of Docker storage driver instructions, overlay can be used but not recommended, preferably using overlay2, the kernel needs more than 4.0, or CentOS7 kernel in 3.10.0-693, requires additional setup parameters.
07-CENTOS7 users, the kernel in 3.10.0-693 or more, Docker-ce v17.06 and above, in the use of Overlay2 driver, you also need to set additional parameters to prohibit detection of the kernel version 4.0.
Reference Links:
Install Docker v17.03 under CentOS7
https://docs.docker.com/v17.03/engine/installation/linux/centos/#install-from-a-package
Use the Device Mapper storage driver
https://docs.docker.com/v17.03/engine/userguide/storagedriver/device-mapper-driver/
Use the OVERLAYFS storage driver
https://docs.docker.com/v17.03/engine/userguide/storagedriver/overlayfs-driver/
CentOS Modify Devicemapper Storage drive to DIRECT-LVM mode
Https://forums.cnrancher.com/article/19
Use the Device Mapper storage driver
https://docs.docker.com/storage/storagedriver/device-mapper-driver/
Installation of Docker under CentOS
https://docs.docker.com/v17.03/engine/installation/linux/centos/#install-from-a-package
Configure DIRECT-LVM mode for production
https://docs.docker.com/v17.03/engine/userguide/storagedriver/device-mapper-driver/# Configure-direct-lvm-mode-for-production
Docker question and Answer video (100)
https://blog.lab99.org/post/docker-2016-07-14-faq.html# Docker-de-var-lib-docker-devicemapper-zhan-yong-kong-jian-bu-duan-zeng-chang-zen-me-po
Redhat7.2_release_notes (OVERLAYFS)
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/7.2_release_notes/ Technology-preview-file_systems
Redhat7.3_release_notes (OVERLAYFS)
Https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/7.3_release_notes/technology_ Previews_file_systems
Redhat7.4_release_notes (OVERLAYFS)
Https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/7.4_release_notes/technology_ Previews_file_systems