LinuxQuestions.org
Visit Jeremy's Blog.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices

Reply
 
Search this Thread
Old 07-02-2009, 06:06 AM   #1
karuna-bdc
LQ Newbie
 
Registered: Oct 2008
Location: Nilai, Malaysia
Distribution: Ubuntu
Posts: 17

Rep: Reputation: 0
what are initrd.img-2.6.28-11-generic and vmlinuz-2.6.28-11-generic?


Im looking at my menu.lst file for GRUB, and I just wanna understand it a bit better, and I have entries like :
Code:
title		Ubuntu 9.04, kernel 2.6.28-11-generic
uuid		a139b05b-3924-4499-9ff4-975b37b7a20c
kernel		/boot/vmlinuz-2.6.28-11-generic root=UUID=a139b05b-3924-4499-9ff4-975b37b7a20c ro quiet splash 
initrd		/boot/initrd.img-2.6.28-11-generic
quiet

title		Ubuntu 9.04, kernel 2.6.28-11-generic (recovery mode)
uuid		a139b05b-3924-4499-9ff4-975b37b7a20c
kernel		/boot/vmlinuz-2.6.28-11-generic root=UUID=a139b05b-3924-4499-9ff4-975b37b7a20c ro  single
initrd		/boot/initrd.img-2.6.28-11-generic
and Im guessing that title just gives the title of the O/S im booting into if selected, and im guessing that vmlinuz .. is the actual linux kernel? am I right? Ok so whats the initrd thing? I googled it and I got loads of stuff about initial ram disks but im still not sure what they do. and after the kernel line, there are options like ro and single and quiet and splash.. what do they do?

haha im really interested in learning how stuff works, will be real glad if you all could point me in the right direction!

THanks in advance!
 
Old 07-02-2009, 06:39 AM   #2
monsm
Member
 
Registered: Feb 2005
Location: London, UK
Distribution: Gentoo
Posts: 568

Rep: Reputation: 37
Yes, you are right. vmlinuz is the Linux kernel. The text on that line tells you the kernel is Linux version 2.6.28-11 and its the generic build by the ubuntu team. The uuid identifies which partition is the root partition to use.

The initrd file is the boot image for the initial ram disk that is sometimes used to get the kernel and any modules into memory. This is sometimes necessary for some hard disk setups (like encryption and raid). It is also used to do the fancy flash images you see during the boot process.

The other parameters there says. Start the files system initially (during boot itself) as read-only (ro), and on the first entry, boot quiet and show the fancy splash image and progress bar. This hides all the details of the boot itself.

The second one is the recovery mode which you use if something isn't working. It boot with single user only and you will see all the details of the boot process and any error messages.

Hope that helps.

Mons
PS! Waow thats my 500ths post. Guess I have been here a while already. Time flies

Last edited by monsm; 07-02-2009 at 06:42 AM.
 
Old 07-02-2009, 06:39 AM   #3
xeleema
Member
 
Registered: Aug 2005
Location: D.i.t.h.o, Texas
Distribution: Slackware 13.x, rhel3/5, Solaris 8-10(sparc), HP-UX 11.x (pa-risc)
Posts: 987
Blog Entries: 4

Rep: Reputation: 249Reputation: 249Reputation: 249
You're on the right track!

"title" is the name of the menu option that the GRUB bootloader displays.

"vmlinuz-*" is the Linux kernel itself, in compressed form (typically bzip2 or gzip).

"initrd-*" is a mini filesystem-in-a-file stuffed full of things that the kernel will need prior to actually initializing the remaining hardware and firing off init-scripts.

(Basically, if you have kernel modules for things like SCSI cards, sound, etc, then they get stuffed in this file by "mkinitrd").

The "initrd-*" file gets dumped into a ram disk (a virtual disk cut out of your ram), so the kernel can finish loading-up.

As for the options like "ro", "single", "quiet" and "splash";

"splash" sets the background of the GRUB menu. This can be changed to something more unique to give the server a bit more personality.

"ro" just means "read only" (necessary, I wouldn't mess with that one)

"single" drops the server into "Single User Mode" (think "Safe Mode", only it works better)

I'm not sure about "quite", however there should be a grub.conf man page that explains that one better.

Hope this helps!
 
Old 07-02-2009, 07:40 AM   #4
karuna-bdc
LQ Newbie
 
Registered: Oct 2008
Location: Nilai, Malaysia
Distribution: Ubuntu
Posts: 17

Original Poster
Rep: Reputation: 0
Oh ok ok cool. So basically, the initrd is like a temporary filesystem that the kernel uses to finish loading its driver modules etc?

and if i were to get rid of quiet and splash in the options, the ubuntu spash screen wont show up and instead i would get the loading messages like if i were to boot into recovery mode right?

and lets say if i wanted to boot another linux O/S besides ubuntu, all id have to do is give it a title, use blkid to get the root UUID and put it down then find the vmlinuz and initrd in the other distro and put it down as well and thats it?

thanks alot ! feels good understanding things.
 
Old 07-02-2009, 08:50 PM   #5
xeleema
Member
 
Registered: Aug 2005
Location: D.i.t.h.o, Texas
Distribution: Slackware 13.x, rhel3/5, Solaris 8-10(sparc), HP-UX 11.x (pa-risc)
Posts: 987
Blog Entries: 4

Rep: Reputation: 249Reputation: 249Reputation: 249
You're on the right track! You should be able to just ditch the "quite" option, then at boot-up, after you've selected an option from GRUB, just tap escape or F2 (I forget which) and the splash screen should drop off, revealing all the Linux wonderment the boot-up process has to offer.

As for booting another OS, that should work. It's been a while since I messed with the underpinnings of GRUB. I think the last time I played with it was to get a Solaris/Windows/Linux trifecta setup on my laptop, and I had to use Sun's build of GRUB (which was a release or two behind).

The biggest advice I can give you is to read up on how to mess with GRUB once it's loaded. A typo in the grub.conf can render you machine "unbootable", however with GRUB you can edit the options "live"!
 
Old 07-02-2009, 10:07 PM   #6
karuna-bdc
LQ Newbie
 
Registered: Oct 2008
Location: Nilai, Malaysia
Distribution: Ubuntu
Posts: 17

Original Poster
Rep: Reputation: 0
Ok cool, ill try that once fedora 11 finishes downloading

thanks alot!
 
Old 07-16-2009, 12:16 AM   #7
SaintDanBert
Senior Member
 
Registered: Jan 2009
Location: Austin, TX
Distribution: Mint-15 with Cinnamon & KDE
Posts: 1,362
Blog Entries: 3

Rep: Reputation: 86
Quote:
Originally Posted by monsm View Post
Yes, you are right. vmlinuz is the Linux kernel. The text on that line tells you the kernel is Linux version 2.6.28-11 and its the generic build by the ubuntu team.
uname --processor --hardware-plarform both report as "unknown"

uname --kernel-version reports "#1 SMP PREEMPT ..."

Review of /var/log/dmesg shows
Code:
CPU1: Intel(R) Core(TM)2 Duo CPU     L7500  @ 1.60GHz stepping 0b
Total of 2 processors activated (6387.24 BogoMIPS).
I have both -generic and -386 editions of vmlinuz files. I don't understand why I have or need both of them.
 
Old 07-16-2009, 02:17 AM   #8
Babertje
Member
 
Registered: Jun 2009
Location: Haarlem, The Netherlands
Distribution: Archlinux
Posts: 125

Rep: Reputation: 20
xeleema said:
"splash" sets the background of the GRUB menu.
This is not accurate, the background of the grub-menu itself is set with the "splash-image" command

I'm not sure about "quite",
The "quiet" command after the initrd line lets grub to be silent when initializing
some types of disk-controllers with more than one disk or raid setup
 
Old 07-16-2009, 02:45 AM   #9
vap16oct1984
Member
 
Registered: Jun 2009
Location: INDIA
Distribution: RHEL-5
Posts: 174
Blog Entries: 3

Rep: Reputation: 38
Lightbulb

First of all thanks to all member for this beautiful discussion. Linux is like the mystery more you know is no enough and more new things come. That is the greatness of linux never ending like a legend.

Well Xeleema,
i want to discuss you about this quote. I have used Redhat all versions,suse,fedora,Ubanto with windows versions. What i found interesting about this quote is Solaris.
Quote:
Originally Posted by xeleema View Post
I think the last time I played with it was to get a Solaris/Windows/Linux trifecta setup on my laptop, and I had to use Sun's build of GRUB (which was a release or two behind).

Now i want to install solaris in my laptop? Is it possible and how can i install this on laptop. From where i can download solaris iso image that
runs on my laptop.

Just give me the download link of Solaris that will run on my lAPTOP.

Thanks a lot in advance.
 
Old 07-16-2009, 05:45 AM   #10
xeleema
Member
 
Registered: Aug 2005
Location: D.i.t.h.o, Texas
Distribution: Slackware 13.x, rhel3/5, Solaris 8-10(sparc), HP-UX 11.x (pa-risc)
Posts: 987
Blog Entries: 4

Rep: Reputation: 249Reputation: 249Reputation: 249
vap16oct1984,

If you want to find Solaris for your laptop, just go to Sun.com and download the "x86" version of Solaris 10 (not the "SPARC" version).

Sun doesn't provide direct links to their ISOs, because they like everyone to have an account on their site (which is *really* hand for getting patches, security updates, and posting to their forums).

I had a few quirks with my keyboard right after the installation, but I was able to find and add a few things into my X server config file to take care of that.

By the way, set up Solaris 10 x86 on my then-brand-new Dell M1210 laptop.

If you're serious about getting Solaris, Linux, and Windows on an x86 system of any kind, I would strongly suggest you do the following (it took me a few tries to figure this out);

0) Solaris 10 packs it's own GRUB for booting UFS filesystems and understanding the Solaris layout. Don't let this get overwritten with a Linux distribution's GRUB. All GRUB management has to be done from the Solaris side of your machine (once it's all setup).

1) If you already have a Windows OS on your system, use a 3rd party partition resizer to shrink it down. (I used Partition Magic, a commercial app). Be sure to keep Windows at the "front" of your drive.

2) Install your Linux distro in one solid Primary Partition. Don't get crazy with filesystems, and don't setup a dedicated swap partition (configure a swap *file* later). This is necessary because during the Solaris 10 installation, it will "see" the swap partition and load it's mini-installer into that (which panics your Linux install).
Take note of the GRUB entries it sets up. Write them *all* down if you have to.

3) Install an x86 build of Solaris 10. Then go into the GRUB config and throw in the Linux and Windows specific things you found.

As a side note, keep in mind that I don't have to worry about swap during the installation. It helps when you have 2GB of RAM Also, nVidia video seems to make things go easier (at the time ATi video drivers were a huge pain to deal with).

Good luck!
 
Old 07-16-2009, 07:01 AM   #11
stratotak
Member
 
Registered: Sep 2005
Distribution: Today Debian . Tomorrow ..??
Posts: 386

Rep: Reputation: 39
Just to add..Maybe some body is reading this post and sees "quiet" and "silent"..and are taking that literally..as in sound...Like the pc makes beep codes or something as it boots...Quiet option in grub just means at boot..it doesn't show everything its doing in text..
 
Old 07-17-2009, 05:00 AM   #12
vap16oct1984
Member
 
Registered: Jun 2009
Location: INDIA
Distribution: RHEL-5
Posts: 174
Blog Entries: 3

Rep: Reputation: 38
Thanks Xeleema,
Let me try all this...well thanks a lot. Its was a great advice.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Generic SMP kernel with no initrd? songangel Slackware 8 03-26-2009 06:12 PM
/vmlinuz /initrd.img links ninj4fly Linux - Newbie 4 02-19-2008 08:33 AM
Is it possible to update the pxe network install initrd.img and vmlinuz ? lets-eat-gary Fedora 1 08-22-2006 04:54 AM
How to update the pxe network install initrd.img and vmlinuz ? lets-eat-gary Linux - Networking 3 08-20-2006 03:45 PM
how to encrypt initrd.img and decrypt in vmlinuz. AshesOfTime Programming 1 12-09-2004 03:48 PM


All times are GMT -5. The time now is 09:11 PM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration