crontab is an extremely useful tool in Linux for scheduling scripts and programs to run at specified times. Below we use a MySQL backup script as an example to illustrate. Here’s how to execute the backup.sh script at 23:00 every day:
crontab -e
Enter the following code, then save with shift+z+z:
0 23 * * * /ho …
The sync task in crontab didn’t execute yesterday, and I don’t know why — it seemed to hang. I wanted to investigate what went wrong with crontab or where it got stuck.
1. linux
Check the /var/log/cron file. You can use tail -f /var/log/c …
How to Change Linux YUM Repository Source
Step 1: Enter the yum configuration directory: cd /etc/yum.repos.d/Step 2: Backup the configuration file: mv CentOS-Base.repo CentOS-Base.repo.bakStep 3: Download the NetEase configuration (or another repository configuration file): wget http://mirrors.163.com/.he …
I was planning to use wget to download the Hadoop compressed package, but ended up getting the following error: [root@linyuhe mnt]# wget http://mirror.cnop.net/nagios/nagios-plugins-1.4.14.tar.gz -bash: /usr/bin/wget: Permission deniedEven the root account reported a permission error, and …
When installing software with yum, the following message appears: another app is currently holding the yum lock;waiting for it to exit
Sometimes when upgrading files with yum, you may encounter the following situation:
another app is currently holding the yum lock;waiting f …
While setting up a Varnish cache server environment today, I ran into an issue during installation. When running the configure script, it threw the following error:
configure: error: readline library not found
I had already installed the readline package on the system before this happened.
…
Here is an example: Before modifying /etc/network/interfaces, it’s best to back it up firstcp /etc/network/interfaces /etc/network/interfacesbackupiface eth0 inet staticaddress 192.168.0.16netmask 255.255.255.0gateway 192.168.0.1 …
hdparm can detect, display, and set parameters for IDE or SCSI hard drives. It is a shell utility in Linux for viewing and modifying IDE drive parameters.
1. Installation, the command is as follows:
yum -y install hdparm
2. Run:
hdparm -tT /dev/xvdb1
The device name above is …
If you encounter the “550 create directory operation failed” error, it’s usually caused by the SELinux security mechanism. Simply disable SELinux to resolve it: # vi /etc/selinux/configChange SELINUX=XXX –>XXX represents the level
to SELINUX=dis …
The RHEL ISO does not include it, so you’ll need to download the source package from a third-party site and compile it for installation. This software also has a Windows version. It can report network interface traffic status and view the bytes sent and received by the NIC, generating data once per second. 1. ifstat installation wget http://gael.roualland.f …
