The easiest way to change the hostname on AlmaLinux 8, CentOS 8, and Rocky Linux 8 is to use the hostnamectl command. First I will check the current hostname by running "hostnamectl status" on the shell of my server: hostnamectl status The output on my system is: [root@server1 ~]# hostnamectl status Static hostname: server1.example.com Icon ... Read more
Dovecot is watching the whole server filesystem for modifications and removed or added sub filesystems. If you get errors similar to this one on your server: Aug 30 09:10:23 server1 dovecot: master: Warning: /var/www/clients/client1/web1/log is no longer mounted. If this is intentional, remove it with doveadm mount (the directory path may vary), then you can ... Read more
If you use the apache mod_security module on your apache server, you might encounter wrong 403 errors for several URL's of the cms systems. Here are some exception rules to avoid that: For WordPress Blogs <locationmatch "/wp-admin/admin-ajax.php"> SecRuleRemoveById 300013 SecRuleRemoveById 300015 SecRuleRemoveById 300016 SecRuleRemoveById 300017 </locationmatch> <locationmatch "/wp-admin/page.php"> SecRuleRemoveById 300013 SecRuleRemoveById 300015 SecRuleRemoveById 300016 SecRuleRemoveById ... Read more
The usual thing you find when you right-click your desktop to create a new document is the option to create an empty text document. This selection can be widened however by using the Templates folder in your home folder. Any document that is put in there will be selectable; this is also possible with pictures ... Read more
If you get error messages from amavisd similar to the one posted below on a server which is virtualized with OpenVZ: Mar 5 09:09:02 v100 amavis[17378]: (17378-14) (!!)TROUBLE in process_request: Error writing a SMTP response to the socket: Broken pipe at (eval 100) line 987, <GEN44> line 31. then the issue can be caused by ... Read more
Follow these steps to disable IPv6 on CentOS. Edit the /etc/sysctl.conf file, I will use the nano editor here: nano /etc/sysctl.conf And add the following line at the end of the file: net.ipv6.conf.all.disable_ipv6 = 1 Then run: sysctl -p to load the new settings. The next step is to edit the network card configuration file (/etc/sysconfig/network-scripts/ifcfg-eth*) ... Read more
Centos 7 replaced the traditional IPTables Linux Kernel Firewall with the Firewalld service. There are still a lot of scripts available that require the use of IPTables. A common example is the software Fail2ban. In this guide, I will explain the installation of IPTables on Centos 7.x The first step is to stop and mask ... Read more