docker volume

 volumes：Docker管理宿主机文件系统的一部分，默认位于 /var/lib/docker/volumes 目录中；（最常用的方式）

[root@compute28 volumes]# docker volume ls
local               kolla_logs
local               libvirtd
local               nova_compute
local               nova_libvirt_qemu

[root@compute28 volumes]# docker volume inspect   kolla_logs
[
    {
        "CreatedAt": "2020-08-27T11:58:36+08:00",
        "Driver": "local",
        "Labels": null,
        "Mountpoint": "/var/lib/docker/volumes/kolla_logs/_data",
        "Name": "kolla_logs",
        "Options": null,
        "Scope": "local"
    }
]

docker system df命令，类似于Linux上的df命令，用于查看Docker的磁盘使用情况

[root@compute28 volumes]#  docker system df 
TYPE                TOTAL               ACTIVE              SIZE                RECLAIMABLE
Images              10                  10                  4.562GB             1.66GB (36%)
Containers          25                  17                  1.325GB             0B (0%)
Local Volumes       28                  28                  85.97GB             0B (0%)
Build Cache         0                   0                   0B                  0B
[root@compute28 volumes]# 

 docker ps | grep nova
84d9df293c4b        registryserver:4000/ nova-compute:4.0.2-2.3.4                "kolla_start"            12 months ago       Up 12 months                            nova_compute
11419ad00507        registryserver:4000/ libvirt:4.0.2-2.3.4                "kolla_start"            12 months ago       Up 12 months                            nova_libvirt
db1261c1c690        registryserver:4000/ nova-ssh:4.0.2-2.3.0                    "kolla_start"            12 months ago       Up 12 months                            nova_ssh

[Note] System unauthorized, Please contact the system supplier.

[Unauthorized System] root@T920compute24:/var/lib/docker/volumes/nova_compute/_data/instances/30d90530-6a13-496d-a8cb-a25464e1cb59# docker inspect nova_compute

Volume管理
创建一个Volume：

$ docker volume create my-vol
查看Volumes：

$ docker volume ls
local my-vol

$ docker volume inspect my-vol
[
{
"Driver": "local",
"Labels": {},
"Mountpoint": "/var/lib/docker/volumes/my-vol/_data",
"Name": "my-vol",
"Options": {},
"Scope": "local"
}
]
我么可以看到创建的Volume my-vol保存在目录/var/lib/docker/volumes/下，以后所有针对该Volume的写数据都会保存中目录/var/lib/docker/volumes/my-vol/_data下。
删除一个Volume：
$ docker volume rm my-vol
或者删除所有未使用的Volumes：
docker volume prune