1、docker-compose啟的nexus倉庫意外dead
公司的maven私服nexus是通過docker-compose啟動的，不知道什么原因意外死掉了。再次啟動的時候報錯：
[root@test-java nexus]# docker-compose up -d
Removing nexus_nexus_1
ERROR: driver "overlay" failed to remove root filesystem for 738f492a57f80951b279c3bd82f59b6230275a298ab74d7f26c4564cf3d1cf2c: remove /var/lib/docker/overlay/6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887/merged: device or resource busy
2、原因分析
看報錯應該是之前的容器無法刪除導致的，device or resource busy應該是還有某些進程在占用。
3、處理問題
先通過docker rm命令嘗試刪除該容器：
[root@test-java nexus]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
141d9363cf95 jenkins "/bin/tini -- /usr..." 12 days ago Exited (137) 10 days ago jenkins
85e5f06d1344 jenkins "/bin/tini -- /usr..." 12 days ago Exited (130) 12 days ago reverent_ritchie
738f492a57f8 sonatype/nexus3 "bin/nexus run" 2 weeks ago Dead nexus_nexus_1
eef939679dd1 nginx:1.13.3 "/usr/local/nginx/..." 2 months ago Created 443/tcp, 0.0.0.0:8087->80/tcp nginx2
5087229bf9aa nginx:1.13.3 "/usr/local/nginx/..." 2 months ago Exited (0) 2 weeks ago nginx
c67cf4bdefd9 sonatype/nexus3 "bin/nexus run" 9 months ago Dead c67cf4bdefd9_nexus_nexus_1
[root@test-java nexus]# docker rm 738f492a57f8
Error response from daemon: driver "overlay" failed to remove root filesystem for 738f492a57f80951b279c3bd82f59b6230275a298ab74d7f26c4564cf3d1cf2c: remove /var/lib/docker/overlay/6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887/merged: device or resource busy
無法正常刪除，嘗試強制刪除：
[root@test-java nexus]# docker rm -f 738f492a57f8
Error response from daemon: driver "overlay" failed to remove root filesystem for 738f492a57f80951b279c3bd82f59b6230275a298ab74d7f26c4564cf3d1cf2c: remove /var/lib/docker/overlay/6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887/merged: device or resource busy
通過docker rm無法刪除，提示文件系統相關的問題，應該是和docker容器的文件系統有關，docker是通過掛載的形式使用宿主機文件系統的。查看一下跟報錯有關的掛載信息：
[root@test-java nexus]# grep docker /proc/*/mountinfo|grep 6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887
/proc/814/mountinfo:80 79 0:38 / /var/lib/docker/overlay/6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887/merged rw,relatime - overlay overlay rw,lowerdir=/var/lib/docker/overlay/e580d619ecdb1aeb01f73ad07d727812a3f9776af5af0679eecfd60198884aaf/root,upperdir=/var/lib/docker/overlay/6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887/upper,workdir=/var/lib/docker/overlay/6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887/work
注意：
6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887這串數字是和報錯中的一致的。
可以看到有跟該容器相關的掛載信息仍然處於掛載中，所以導致無法刪除。
獲取該掛載進程的pid並殺掉該進程：
[root@test-java nexus]# grep docker /proc/*/mountinfo|grep 6031651302dba6053c5fde07937f4fd00dfc063577fa343b12c83f1c26b77887 | awk -F ":" '{print $1}' | awk -F "/" '{print $3}'
814
[root@test-java nexus]# kill -9 814
重新啟動nexus：
[root@test-java nexus]# docker-compose up -d
Removing nexus_nexus_1
Recreating c67cf4bdefd9_nexus_nexus_1 ... error
ERROR: for c67cf4bdefd9_nexus_nexus_1 b'driver "overlay" failed to remove root filesystem for c67cf4bdefd9746ab850d09960211b02d0d184aa5e7c602095b1acdee57dc813: remove /var/lib/docker/overlay/ec743b1c55a524fd85421621314aa5acd44a29601f917f1f2eaed5f1a6d6c727/merged: device or resource busy'
ERROR: for nexus b'driver "overlay" failed to remove root filesystem for c67cf4bdefd9746ab850d09960211b02d0d184aa5e7c602095b1acdee57dc813: remove /var/lib/docker/overlay/ec743b1c55a524fd85421621314aa5acd44a29601f917f1f2eaed5f1a6d6c727/merged: device or resource busy'
ERROR: Encountered errors while bringing up the project.
還有這樣的報錯，說明還有相關的掛載進程沒有停止掉。找出進程並殺掉：
[root@test-java nexus]# grep docker /proc/*/mountinfo|grep ec743b1c55a524fd85421621314aa5acd44a29601f917f1f2eaed5f1a6d6c727 | awk -F ":" '{print $1}' | awk -F "/" '{print $3}'
20910
21073
[root@test-java nexus]# kill -9 20910
[root@test-java nexus]# kill -9 21073
-bash: kill: (21073) - No such process
再次啟動：
[root@test-java nexus]# docker-compose up -d
Removing nexus_nexus_1
Recreating c67cf4bdefd9_nexus_nexus_1 ... done
[root@test-java nexus]#
啟動成功！