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Rhel 7 boot process

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Booting process of Rhel 7 is way different from other rhel distro. So here we are going to explore the booting process by assuming this , we have grub2  as a boot loader. @@@@  From Power ON to  Rhel 7 Running  @@@@    POST (power on self test) test  by BIOS.     BIOS  scan for possible boot device and orders them to according to user preferences.  Boot device are scanned in order for a boot firmware (MBR,PXE ROM,or a partition mark as bootable) , if found then execute it.   The first stage boot loader stores in  MBR  , which loads the stage 1.5(driver) and stage boot loader from disk and execute it. Now boot loader loads the configuration file from hard disk in case of grub2  is /boot/grub2/grub.cfg . Configuration is parsed and based on its contents a boot entry is selected automatically . The kernel and initial RAMdisk is referenced in the boot entry are located from disk and control is h...
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System Monitoring with Cockpit

Cockpit :    A software developed by RedHat for system admins . *  Its a graphical User interface *  To monitor system *  Also can configure system and performance *  Also provide terminal on the browser  >>    Installing  cockpit  [root@station249 ~]# yum  install cockpit >>  Starting  service [root@station249 ~]# systemctl start cockpit To access :  https://ip:9090 login with any of the server username and password   
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deep dive with journalctl in Rhel 7

Journalctl :  This is one of the most important component of Systemd that is responsible for viewing and managing log files. Note:    You can check by using below command : [root@station227 ~]# pstree   |   grep -i journ       This is very similar to logs in managed by  rsyslogd   that is storing logs persistently but journalctl  storing logs in tmpfs  under  /run/log/  that is not persistent . Important Options:  1.    view all the logs  in verbose mode [root@station227 log]# journalctl  -o verbose -- Logs begin at Thu 2018-08-30 06:58:02 GMT, end at Fri 2018-08-31 07:10:01 GMT. -- Thu 2018-08-30 06:58:02.565541 GMT [s=34f56459bdda420e9fbb3d389c538572;i=1;b=633ca5e2242543daa9c895c1485     PRIORITY=6     _TRANSPORT=driver     MESSAGE=Runtime journal is using 8.0M (max allowed 788.7M, trying to leave...
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