Summary of debian10 system problems

Question 1 ： Ordinary users can't use java -version

resolvent ;Root Granted to ordinary users JAVA jurisdiction

sudo chmod -R 755 java The installation directory 
sudo chown -R [username] java The installation directory 

have already been solved

Problem the disk is full

Go to / Check the file size under

du -sh *

Then look for

Finally find the problem

【 resolved 】docker overlay2 Take up a lot of disk space 

Docker  Clean up data volumes  volumes

 Processing mode 1:
 In the use of docker when , There is often a lack of disk space , The usual cause of the problem is docker The system deployed in the output a lot of log content .

 here , It can be cleared by manual or scheduled tasks .

 in the light of /var/lib/docker/overlay2 There are lots of solutions on the Internet , Some of these misleading claims need to be migrated to the path and other operations . In fact, the occupation of disk space and overlay No problem （ its usage And the real disk usage identical ）, It's just a docker Virtual file system , The real file system is the former /dev/vda1, You can see that the path refers to the root directory , So you're going to find out where the garbage is .

 Usually with overlay2 There will be the following directories in the same level directory of ：

 Check the function of this directory online , be supposed to  overlay/overlay2 Express Docker The storage driver of continues to search for information on the Internet , We can see if there are too many dead containers , Use  docker ps -a Looked at the , Sure enough . So I cleaned up the useless containers , The hard disk will return to normal ……

 Simple way 
 Read more information , Discovery available  docker system prune To automatically clean up space , Refer to the following ：

 This command will clear all the following resources by default ：
 Stopped container （container）
 A volume that is not used by any container （volume）
 A network that is not associated with any container （network）
 All suspended mirrors （image）.
 By default, the command will only clear the dangling image , Unused images will not be deleted .
 add to  -a  or  --all  After the parameter , You can clear all unused images and dangling images at the same time .
 You can add  -f  or  --force  Parameter is used to ignore relevant alarm confirmation information .
 The total amount of space freed by cleanup is displayed at the end of the instruction .
（https://yq.aliyun.com/articles/272173 ）
 in addition , Use the following command to view docker The size of the hard disk , Such as ：
docker system df

Docker  Check data volume and disk usage 
Docker  In case of long-term use , It is often necessary to delete old containers and create new ones , In the long term ,Docker  The data volume  volumes  Will produce a lot of zombie files , These will be robust directories that are mostly unbound containers 

Docker Delete useless data volumes

Manually delete the command

Copy code

 Delete all dangling Data volume （ It's useless Volume, Zombie files ）
docker volume rm $(docker volume ls -qf dangling=true)

 Delete all dangling Mirror image （ That is no tag Mirror image ）
docker rmi $(docker images | grep “^” | awk “{
     print $3}”)

 Delete all closed containers 
docker ps -a | grep Exit | cut -d ’ ’ -f 1 | xargs docker rm
 Copy code 

 Delete closed containers 、 Useless data volumes and networks , as well as dangling Mirror image （ That is no tag Mirror image ）

 Be careful , All closed containers will be deleted , Please check whether there are containers that are closed but need to be kept 

 Delete closed containers 、 Useless data volumes and networks 
docker system prune

 Delete more thoroughly , Can be used without container Docker The images are removed 
docker system prune -a

 restart  Docker

Commands using the above methods can effectively clean up Docker Useless files generated by operation , And there is no need to restart Docker Effective .

Docker The images are removed
docker system prune -a

restart Docker

 Commands using the above methods can effectively clean up  Docker  Useless files generated by operation , And there is no need to restart  Docker  Effective .

 however  Docker  There may be some  bug（ kernel  3.13  Version of  Docker  Diagnosis ）, Lead to  Docker  Unable to clean up some useless directories , But restart  Docker  Can solve this problem