Category Archives: Linux

[Solved] Linux Start solr Error: Your Max Processes Limit is currently 31202. It should be set to 65000 to avoid operational disruption.

Execute the startup specification after entering the bin directory

./solr start

report errors

What should I do?

View system limits

 ulimit -a

Now you need to change the system limit and log in to the root account

Locate the file/etc/security/limits At the end of conf, add the following two lines [added by default in some systems]

* soft nofile 65535
* hard nofile 65535

Then locate the file/etc/security/limits d/20-nproc.conf

Change 4096 to 65535

Login again and take effect after modification

docker pull Error: Get dial tcp getsockopt: connection refused

This problem is encountered when building your own docker warehouse on the intranet because docker does not support HTTP registry by default,

vim /etc/docker/daemon.JSON {“secure registers”: [“hub.Zuobiao.Com”]}

Restart docker

systemctl restart docker. service

Harbor pull code, and you need to log in first:

docker login -u username -p password

[Solved] “/usr/local/bin/docker-compose: Permission denied”

Because the task needs to deploy the docker compose tool environment in the server, I reported the error “/usr/local/bin/docker compose: permission denied” when viewing the version. This error message should be due to insufficient permissions

Authorize at this time:

chmod +x /usr/local/bin/docker-compose

Then check the version and it will be normal

Nginx normal user startup configuration error: && springboot-swagger & Unable to infer base url

2022/01/04 08:50:55 [crit] 8715#8715: *107201 mkdir() “/var/cache/nginx/proxy_temp/3” failed (13: Permission denied) while reading upstream, client:, server: localhost, request: “GET /prod-api/swagger-ui/swagger-ui-standalone-preset.js?v=3.0.0 HTTP/1.1”, upstream: “http://[::1]:8090/swagger-ui/swagger-ui-standalone-preset.js?v=3.0.0”, host: “hostname:9000”, referrer: “http://hostname:9000/prod-api/swagger-ui/index.html”. 


Looking at the nginx log, there is no /var/cache/nginx/proxy/temp permission. Authorize it.
sudo chmod a+w /var/cache/nginx/proxy_temp -R

How to Install nginx yum:

Add repo of nginx:

echo '[nginx]
name=nginx repo
enabled=1' > /etc/yum.repos.d/nginx.repo


yum update
yum install nginx

Did you install the latest version of nginx directly?
log]$ whereis nginx
nginx: /usr/sbin/nginx /usr/lib64/nginx /etc/nginx /usr/share/nginx /usr/share/man/man8/nginx.8.gz

Then you need to configure the normal user path of nginx. Create the relevant directory and copy the configuration file. Authorize proxy_temp. As above.
log]$ mkdir -p /data/nginx/log /data/nginx/run  /data/nginx/conf.d
log]$ cp /etc/nginx/nginx.conf /data/nginx/
log]$ cp /etc/nginx/conf.d/default.conf /data/nginx/conf.d/
sudo chmod a+w /var/cache/nginx/proxy_temp -R
log]$ vi /data/nginx/nginx.conf

#user  nobody;
worker_processes  auto;

error_log  /data/nginx/log/error.log notice;
pid        /data/nginx/run/;

events {
    use epoll;
    worker_connections  1024;

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /data/nginx/log/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

    include /data/nginx/conf.d/*.conf;

Hope this article will help you.

Error: listen EADDRINUSE: address already in use :::80 [How to Solve]

The port is occupied. There may be a conflict between the port settings of the previous project and the current project.

1. Open the terminal

2. Enter netstat - ano | findstr 80

3. Find the PID occupied by port 80

4. Execute the close command, tskill + PID, and terminate the port operation.

Git pull Error: error: Your local changes to the following files would be overwritten by merge:

In this case, how to keep the local changes while merging the remote ones?

First, it depends on whether you want to save local changes(yes/no)


git stash  
git pull origin master  
git stash pop

git stage will take your local snapshot, and then git pull will not stop you. After the pull, your code does not retain your modifications. Surprised! Don’t worry, what did we seem to have done before


At this time, execute git stash pop. When you go to the local area, you will find that the conflicting local modifications are still there. At this time, you can commit and push whatever you want.


Since you don’t want to keep the local changes, it’s easy to do. Directly restore the local state to the previous commit ID. Then use the remote code to directly overwrite the local code.

git reset --hard 
git pull origin master

nginx Server Start Error: nginx: [emerg] open() “/var/run/nginx/” failed (Linux Restart)


After Linux restarts, an error is reported when starting the nginx server


1. Use the command CD/usr/local/nginx/conf to enter the specified directory

2. Use the command VI nginx Conf modify the configuration file # and remove the # number in the figure

3. Change to PID/usr/local/nginx/logs/;

4. Use the command MKDIR/usr/local/nginx/logs to create a directory

5. Start nginx service

[Solved] 1.4pip Install xgboost Error: Command errored out with exit status

If you can’t install it on pip, you can go to Python extension packages for windows – Christoph gohlke (UCI. EDU) to find what you need to install. For example, if I can’t install xgboost, search for xgboost here

Find the WHL file that matches your own Python Version (the file name and version supported by PIP), such as Python 3.0 represented by cp38.8;

You can enter Python – M PIP debug — verbose in CMD to view the file names and versions supported by your PIP:

After downloading the file, put the file in the same level directory of your Python running file and run PIP install # xgboost-1.5.1-cp38-cp38-win32.WHL (what I need is xgboost-1.5.1-cp38-cp38-win32.WHL)

Linux Files Save Error: E325: ATTENTION [How to Solve]

Error Messages:

Found a swap file by the name “”
owned by: root dated: Thu Jan 1 12:02:39 2022
file name: /
modified: YES
user name: root host name: wang.localdomain
process ID: 10718 (still running)
While opening file “”
dated: Thu Jan 1  12:02:39 2022
(1) Another program may be editing the same file. If this is the case,
be careful not to end up with two different instances of the same
file when making changes. Quit, or continue with caution.
(2) An edit session for this file crashed.
Error: If this is the case, use “:recover” or “vim -r”
to recover the changes (see “:help recovery”).
Error: If you did this already, delete the swap file “”
to avoid this message.



First use (individual tutorials have said that the deleted files are in the root directory, at least I didn’t find them)
ls -a
to see if there is a .swp file that opens with an error
For example, the one I opened with an error was
In this file directory use ls -a

Then use rm -f

Then the error report disappears.

[Solved] fsync: failed to connect to (

The server address has been updated, the original address has been updated to the new address
You need to change the URL of the corresponding command:


vim /usr/sbin/greenbone-nvt-sync
vim /usr/sbin/greenbone-scapdata-sync
vim /usr/sbin/greenbone-certdata-sync

We are seeing no further transitions from old server to new server Since the server will simply not be available beyond September 30th, we decided the following steps to make all users of the deprecated server aware of the situation:

  • On September 1st 2020 we stop updating the Greenbone Community Feed as served via
  • On the same day we add a VT that alerts for any scanned host a highest severity and it will inform about the options to either change the server name for the Greenbone Community Feed or to go with a professional Greenbone product.

and replacing the url, it started downloading the feeds!

Please note that this is not required if you have build GVM-20.08 as this release already includes the sync script pointing at the updated feed server.

If you had to change the URL you probably have some older sync scripts in your PATH which takes precedence over the updated ones from GVM-20.08.

I would strongly suggest to check how you have build your setup and to remove remains / leftovers from your old installation (at least the sync scripts are still the ones from an older GVM installation if you had to change the URL).

If the suggestion isn’t followed you might get into trouble into the future due to using outdated sync scripts not getting any updates.