Comments on: 10 boot time parameters you should know about the Linux kernel

By: ZackY

ZackY — Sun, 11 Dec 2011 15:54:44 +0000

Dear Linux geeks,

I am facing this problem, while i started to develop PHP websites using LAMP on Fedora15, i followed the instructions from following link:

http://tagbeep.com/doc/?page_id=118

where i skipped the point no 1, as i didnt wanted to go for a cli mode or change the runlevels, instead i skipped this
==================================================================
1. Stop x, change run level to 3
The inittab file is gone in fedora 15, we now have to remove a symlink and make a new one using:
rm /etc/systemd/system/default.target
ln -sf /lib/systemd/system/multi-user.target /etc/systemd/system/default.target
If you need X and Gnome just type – start x to go tu run level 5.

==================================================================
and continued, using GEDIT i disabled selinux:
#gedit /etc/selinux/config

setting: SELINUX=disabled

and also saw underlying WARNING that doing this could mess up with my booting, as it says in the guide:

“if you mess up selinux and the machine dosn’t boot, just press F8 at boot time and add selinux=0 to the bootloader parameters”.

i followed the same, and upon reboot, the system said, could not find policy file at location /etc/selinux/policy blah blah… (the warning comes as a fullstop on boot process and in RED COLOR.

any ways i hard rebooted pc, and upon boot pressed “f8 key on keyboard” and i got the grub boot menu, there i selected on first line of it, and added the parameter after rhgb quit (i gave a space and added) selinux=0

but still could not boot properly.

any suggestions? should i boot from INSTALL DVD and goto rescue mode and then at the same location, re-edit file back from “SELINUX=disabled” to “SELINUX=enforced”

plesae if someone encountered such scenario do share how to overcome or any one who can help???

Thnx a lot.

By: Chris Peterman

Chris Peterman — Tue, 11 Oct 2011 18:17:04 +0000

One more that is useful is just “x” where x is 1-6, lets you boot to a specific runlevel

By: Brian Micek

Brian Micek — Sun, 15 May 2011 22:44:38 +0000

With Redhat and Fedora Linux, the initrd filesystem might pause the system boot forever waiting for a LUKs password if any encrypted LUKs devices are detected. This could include a USB memory stick accidentally plugged into the system. The symptoms of this problem are your computer will not boot unattended which might be undesirable. You can undo this behavior with the kernel command argument: “rd_NO_LUKS”

By: darkfader

darkfader — Mon, 18 Apr 2011 23:47:55 +0000

it depends on the filesystem whether you can run fsck while it’s mounted r/w. some can do it[*], the majority can’t.
I don’t know what makes the technical difference which allows them to do it.

[*]most notable veritas vxfs, and to less fun extent xfs, zfs of course.

By: Veerendra Jonnalagadda

Veerendra Jonnalagadda — Sat, 22 Aug 2009 07:14:53 +0000

how does Linux handle new hardware that we found but not initialised like windows show “New Hardware Found” and also how does it handle their device ID and Vendor Ids…..
at the boot time
Regards
Veerendra Jonnalagadda

By: cepal

cepal — Fri, 04 Jul 2008 11:44:29 +0000

for disabling selinux you need to use “selinux=0″, the equal sign is “a bit” missing on your site…

By: John

John — Thu, 01 May 2008 03:36:46 +0000

So what is the option to stop it or at least prompt you during the loading of hardware drivers? my ubuntu 8 upgrade is hanging on the broadcom wireless driver. Debug/recovery mode shows me the hang…

By: fest3er

fest3er — Sat, 26 Apr 2008 20:25:34 +0000

There are two ways to re-view boot messages. First, you can you the command ‘dmesg|less’ to see much of what appears on the console when linux boots. Second, you can ‘cd /var/log’ and look at the contents of the files. Specifically, ‘messages’, ‘daemon’ and ‘syslog’ will contain more information about what the system does during boot and during operation.

By: Mahnaz

Mahnaz — Mon, 14 Apr 2008 09:12:35 +0000

Hi
thank you for the usefull docs
my linux is too fast and i am beginner and need too recognize every line during system boot,how can I change the time and have enough time to see every line of system boot!!!??
Could you add this item to your helpfull site?
Thank you.
—
Regards
Mahnaz

By: Kresten Hartvig Klit

Kresten Hartvig Klit — Wed, 23 Jan 2008 20:53:28 +0000

Thank you for a very distinct and clear survey at the kernel parameters. I can use that!

By: Hareesh

Hareesh — Tue, 01 Jan 2008 03:59:05 +0000

Great,
A few more are there like apm=off, acpi=off, nodma,etc

By: Golam Kibria

Golam Kibria — Sun, 30 Dec 2007 09:20:14 +0000

I want to know the details command step by step.

By: Anonymous

Anonymous — Thu, 23 Mar 2006 19:35:00 +0000

If lilo boot screen doesn’t come with the “boot:” prompt is possible to obtain it with the ‘shift’ key, or, in case of framebuffer enabled, ‘tab’ key.

By: monk

monk — Thu, 09 Mar 2006 23:03:00 +0000

>What maybe lack in this article is: “How to begin the enter parameters mode?”

Thanks, just little info added as per your suggestion :)

By: Anonymous

Anonymous — Thu, 09 Mar 2006 21:53:00 +0000

What maybe lack in this article is: “How to begin the enter parameters mode?”
I guess that, with knoppix, I can enter these in the ‘cheatcodes’ field, at start. But what about a regular lilo or grub boot, and typing this parameters on the fly, without put fingers into lilo.conf or menu.lst?

By: Anonymous

Anonymous — Thu, 09 Mar 2006 10:57:00 +0000

Hey, nice list but don’t forget

vga=ask

It will help if you have problems releated to vga card (change the startup video mode)