CentOS 7配置Docker Storage

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CentOS 7配置Docker Storage 博客分类： docker

背景

CentOS 7已经集成了Docker Engine, 并且提供了docker-storage-setup服务来帮助配置docker服务的devicemapper存储驱动，如果该驱动自动配置失败，则docker服务的存储驱动会降级为lvm-loop驱动。由于loop设备的缓存问题，lvm-loop模式不适合生产环境。

CentOS 7的安装程序默认使用lvm模式管理磁盘，如果仅有一块磁盘，安装程序会在该物理卷(pv)上创建centos卷组(vg), 并同时使用所有空间创建home和root逻辑卷(lv)。

服务docker-storage-setup默认会尝试使用root文件系统所属的vg, 即centos vg，但是由于该vg上已经没有剩余空间，从而导致devicemapper驱动配置失败。

减小home lvm的大小创建docker lvm

CentOS 7默认安装程序创建的home lv空间一般比较大，先减小其大小:

lvresize -L -50G /dev/centos/home

重新创建并挂载home文件系统

umount /home
mkfs.xfs /dev/centos/home
mount /home

使用docker-storage-setup配置devicemapper驱动, 执行:

servicedockerstop
rm -rf /var/lib/docker
servicedockerstart

添加新的存储设备创建docker lvm

停止docker服务，并清除已有的docker storage:

servicedockerstop
rm -rf /var/lib/docker

编辑/etc/sysconfig/docker-storage-setup:

DEVS=/dev/sdb
VG=docker

配置devicemapper驱动：

[root@localhost ~]# docker-storage-setup
INFO: Volumegroupbackingrootfilesystemcouldnot bedetermined
INFO: Device /dev/sdbis alreadypartitionedand is partofvolumegroupdockerRoundingupsizeto fullphysicalextent 12.00 MiBLogicalvolume "docker-poolmeta" created.Logicalvolume "docker-pool" created.WARNING: Convertinglogicalvolumedocker/docker-pooland docker/docker-poolmetato pool's dataand metadatavolumes.THIS WILLDESTROYCONTENTOFLOGICALVOLUME (filesystemetc.)Converteddocker/docker-poolto thinpool.Logicalvolume "docker-pool" changed.

重启docker服务:

servicedockerstart

确认配置生效: a) vg信息:

[root@localhost ~]# vgdisplay--- Volumegroup ---VGName              dockerSystemIDFormat                lvm2MetadataAreas        1MetadataSequenceNo  6VGAccess            read/writeVGStatus            resizableMAXLV                0CurLV                1OpenLV              0MaxPV                0CurPV                1ActPV                1VGSize              10.00 GiBPESize              4.00 MiBTotalPE              2559AllocPE / Size      1028 / 4.02 GiBFree  PE / Size      1531 / 5.98 GiBVGUUID              v1eiA1-P7CS-pUx9-D0uS-eVwZ-41pA-SKdlef

b) docker info:

[root@localhost ~]# docker info
Containers: 0Running: 0Paused: 0Stopped: 0
Images: 0
ServerVersion: 1.10.3
StorageDriver: devicemapperPoolName: docker-docker--poolPoolBlocksize: 524.3 kBBaseDeviceSize: 10.74 GBBackingFilesystem: xfsDatafile:Metadatafile:DataSpaceUsed: 20.45 MBDataSpaceTotal: 4.287 GBDataSpaceAvailable: 4.266 GBMetadataSpaceUsed: 40.96 kBMetadataSpaceTotal: 12.58 MBMetadataSpaceAvailable: 12.54 MBUdevSyncSupported: trueDeferredRemovalEnabled: trueDeferredDeletionEnabled: trueDeferredDeletedDeviceCount: 0LibraryVersion: 1.02.107-RHEL7 (2016-06-09)
ExecutionDriver: native-0.2
LoggingDriver: json-file
Plugins:Volume: localNetwork: bridgenull host
KernelVersion: 3.10.0-327.22.2.el7.x86_64
OperatingSystem: CentOSLinux 7 (Core)
OSType: linux
Architecture: x86_64
NumberofDockerHooks: 2
CPUs: 2
TotalMemory: 1.782 GiB
Name: localhost.localdomain
ID: AY7O:H2RJ:33J5:62FY:GHZE:AGFH:F42E:AH3J:WY7N:JXQK:LHBS:BDKY
WARNING: bridge-nf-call-iptablesis disabled
WARNING: bridge-nf-call-ip6tablesis disabled
Registries: docker.io (secure)

3) Docker Storage配置选项，查看/etc/sysconfig/docker-storage:

DOCKER_STORAGE_OPTIONS="--storage-driver devicemapper --storage-opt dm.fs=xfs --storage-opt dm.thinpooldev=/dev/mapper/centos-docker--pool --storage-opt dm.use_deferred_removal=true --storage-opt dm.use_deferred_deletion=true " http://www.tuicool.com/articles/UFJFRzN

参考

Managing Storage With Docker Formatted Containers

转载于:https://my.oschina.net/xiaominmin/blog/1598665