The crontab command, commonly found in Unix and Linux operating systems, is used to schedule commands for periodic execution. This command reads instructions from the standard input device and stores them in the “crontab” file for later reading and execution. Typically, the instructions stored in crontab are kept …
There are many open-source network monitoring tools available for Linux systems. For example, you can use the iftop command to check bandwidth usage, netstat to view interface statistics reports, and top to monitor currently running system processes. But if you’re looking for a tool that can display real-time network …
Sometimes when storage space is insufficient, we need to clean up useless large files like logs. The following command finds files larger than 800MB in the current directory
# find . -type f -size +800M
…
View user groups:
cat /etc/group
Add:
useradd user1 #Add a new user
usermod -a -G groupA user1 #Add user user1 to the groupA group. …
This command can replace the system’s “rm -rf” when deleting a large number of files and folders causes unresponsiveness.
1. First, install rsync (generally included in most systems; if not, run the following command to install): yum install rsync
2. Create an empty folder (any location): mkdir …
When you compile and install a package from source on Linux, you typically enter the extracted directory and run “configure”. However, sometimes you may encounter an error message like this:
[root@localhost native]# ./configure –with-apr=/usr/bin/apr- …
Yum stores downloaded packages and headers in its cache and does not delete them automatically.
If you find they are taking up disk space, you can use the yum clean command to clear them. More specifically, yum clean headers clears the headers, yum clean packages clears the downloaded …
How to Resize /dev/shm in CentOS 6.x
/dev/shm is a very special directory, mounted by default on system memory with a size of half the total system memory. However, in many cases this size fails to meet our needs. Here’s how to modify its size on a CentOS 6.x system.
1、Edit /etc/fstab #vim /etc/fstabBefore modification …
Note: The following content uses the user zyyh and the CentOS system as an example.
1. Check the OpenSSH software version. To restrict SFTP service users to specific file directories, version 4.8 or above is required.
[root@localhost ftp]# rpm -qa | grep openssh
openssh-server-5.3p1-81.el6_3. …
When using a Linux system, you often run the "free -m" command to check system memory. Let’s learn how to interpret the data this command outputs. free -m
[oracle@iZ~]$ free -m total used free shared buffers …
