Linux How to use, Tutorials and scripts; Guides

Download and Extract SSL certificates After getting an SSL certificate in a zip file via your email, download and extract certificate files (primary and intermediate certificate) to a local directory. Replace old minserv.pem file: Locate miniserv.Pem file (usually in /etc/webmin/). Now it is time to replace mineserv.Pem file with a combination of a private key and primary certificate. Basically, you can create a new miniserv.Pem file in two ways. Run the command : cat private.key yourcommonname.crt > new_miniserv.pem Note: the private.key used in the above command is the file of your private key and

CentOS 6 Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server. You will see a GRUB boot prompt telling you to press any key - you have only a few seconds to press a key to stop the automated booting process. (If you miss this prompt you will need to restart the VM again) At the GRUB prompt, type "a" to append to the boot command. Add the text "single" and press enter. System will boot and you will see the root prompt. Type "passwd" to change the root-password and then reboot again. CentOS 7 Click [View Console] to access the console and click the send CTRL+ALT+DEL button on the top right. Alternatively, you can also click [RESTART] to restart the server. As soon as the boot process starts, press ESC to bring up the GRUB boot prompt. You may need to turn the system off from the control panel and then back on to reach the GRUB bo...

1. Install AIDE package on CentOS/RHEL: # yum install -y aide 2. Check and adjust aide configuration file to fulfill your needs: # vim /etc/aide.conf 3. Initialize AIDE database - it will scan all the files in folders that were included in the config file and save their hash as well as attributes info 4. You may consider keeping golden copy of AIDE database (default is set to /var/lib/aide/aide.db.gz) is secure and read-only location. It will allow you to compare current system integrity to the golden copy. To check what changed run: # aide -C If you get "Couldn't open file /var/lib/aide/aide.db.gz for reading" error it means you need to move database generated in step 3 to this location: #  mv /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz

Error:  fatal: parameter inet_interfaces: no local interface found for ::1 [root@Centos7 postfix]# systemctl restart postfix Job for postfix.service failed because the control process exited with error code. See "systemctl status postfix.service" and "journalctl -xe" for details. [root@Centos7 postfix]# systemctl status postfix.service ● postfix.service - Postfix Mail Transport Agent    Loaded: loaded (/usr/lib/systemd/system/postfix.service; enabled; vendor preset: disabled)    Active: failed (Result: exit-code) since Tue 2018-01-02 16:50:43 IST; 4s ago   Process: 12908 ExecStart=/usr/sbin/postfix start (code=exited, status=1/FAILURE)   Process: 12905 ExecStartPre=/usr/libexec/postfix/chroot-update (code=exited, status=0/SUCCESS)   Process: 12901 ExecStartPre=/usr/libexec/postfix/aliasesdb (code=exited, status=75) Jan 02 16:50:41 Centos7.windows.local systemd[1]: Starting Postfix Mail Transport Agent... Jan 02 16:50:41 Centos7.windo...