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Friday, February 24, 2017

Linux Queries - 1

Query 1 : How to remove commands history permanently.

Ans: We can see commands history by running command:

#history
When we run any commands on server then the commands history gets stored in 2 location
1. In Memory or RAM
2. In HDD under /root/.bash_history

#history -c
will clear the command history from memory & not from HDD.

So if we reboot the server then command history will get loaded again from HDD (/root/.bash_history) into the memory & we can see the commands history again.

So we have to clear it from RAM as well as from HDD. Have to clear file /root/.bash_history as well.

# > /root/.bash_history

Query 2: How to increase timeout of splash screen:

The Splash screen is the picture that you can see while Linux is booting. At the time of booting, if the timeout parameter is less then the splash screen will come and disappear immediately. To interrupt the boot process and to get the splash screen where you can see the kernel  info etc.. it is important to keep the timeout parameter slightly more.
[root@testmachine ~]# grep timeout /etc/grub.conf
timeout=5
[root@testmachine ~]# grep timeout /etc/grub.conf
timeout=1000
Machine will wait for 1000 seconds while booting. But the reboot time will increase if the timeout value is more as machine will wait more to get manual interruption. so when you want to do any activity then only try to increase the timeout parameter and bring it back to default value once you are done with activity.


Thanks,
Kiran Jadhav