Look before you leap, pick your installer carefully 

http://wolvix.org/node/591

Before using an installer for Linux OS, I would first ask, what exactly would the installer do?

Until I have a detailed answer, I don't want to take any risks using a tools I don't know for sure what it is doing, especially installation tools.

That's a lesson I learned the hard way because I remember vividly, when I first try Mandrake years ago, after installation, all my existing partitions and files are gone!!! I know one might not see any lunatic installer like this nowadays, but better be safe than sorry.

Before knowing exactly what an installer does, I would manually do installation myself, though troublesome but safe.

To me, when choosing whether to use the installer or not, there is a most important question — would it install boot loader to MBR or into my Linux boot partition?

Over the years of using Linux, I've formed the habit of installing the boot loader into my Linux boot partition instead of MBR, because MBR seem to be a hot spot everyone is recklessly trying to lay their hands on, especially Windoze, and its ever increasing viruses. I never bothered to create "secure disk" for the tons of Linux OS I've been working on, because installing the boot loader into my Linux partition is my "secure" solution.

The worst case is, e.g., Windoze or its viruses completely hoses MBR and all the Windoze partitions, rendering the box completely unbootable, then the only thing I need to do is:

C:> format /mbr

then reactive my Linux boot partition. Vala, everything would be fine again.

documented on: 2007.07.15, xpt

udev rule for usb boot device 

Newsgroups: gmane.linux.distributions.grml.user
Date: Tue, 23 Jan 2007 16:02:59 -0700
> What is the best/approved udev rule for a usb hard drive to escape
> random drive letter variations /dev/sd[a|b|c|d].

http://forums.devshed.com/linux-help-33/initrd-usb-boot-332584.html

Suggests partition labels over udev for USB boot.

Mark

Initrd & usb boot 

http://forums.devshed.com/linux-help-33/initrd-usb-boot-332584.html

> I run linux off my 40Gb external usb hd.
>
> Usually this appears as /dev/sda, but that changes depending on what else is
> plugged in. i.e. sometimes it might be sdb or sdc etc.
>
> Naturally it is important for linux to know where the / filesystem is so i
> have two entries in grub -> one with root=/dev/sda1 and another with
> root=/dev/sdb1.
>
> Also i have to change the entry for root in /etc/fstab

You can do this with a filesystem label. Make sure your initrd image contains the /sbin/findfs binary (and the shared libraries it needs), then you can set a label for the filesystem ("My-Linux-/" perhaps, and assuming you are using Ext2/Ext3):

# e2label /dev/sda1 My-Linux-/

Then, in the grub config you can use "root=LABEL=My-Linux-/" and have the initrd use findfs to automagically mount the proper root filesystem using this label (using pivot_root and LABEL=My-Linux-/ as the partition identifier and not /dev/sdsomething).

documented on: March 9th, 2006, codergeek42

Boot by UUID or disk label 

Newsgroups: gmane.linux.distributions.grml.user
Date: Thu, 1 Feb 2007 10:11:47 +0100
> Grml wiki indicates that grml can use disk labels/UUIDs as root= option
> for booting [1]. What's the correct syntax for that?

http://michael-prokop.at/blog/2006/08/11/stable-root-device-aka-uuid/

mika

Boot by UUID or disk label 

Upcoming grml releases will very probably use mounting by UUID for main partition (the libata merge of >=2.6.19 forces the decision), I've to make sure the upgrade path works fine for all users then.

> A side question, is the UUID get assigned during mkfs or partition
> creation, or...?

The UUID is usually assigned with running mkfs. Some filesystems provide an interface to change the UUID later on, like with

xfs_admin -U $UUID

mika

Stable root device (AKA UUID) 

http://michael-prokop.at/blog/2006/08/11/stable-root-device-aka-uuid/

Given: server with SCSI disk for the system plus a SCSI storage in the back. who guarantees that /dev/sda is always the systemdisk? Using the Debian-kernel with initramfs isn't capable of booting the system via root=/dev/sda1 because /dev/sda1 corresponds to the SCSI storage.

Generic solution: use the power of UUID:

root@grml # /lib/udev/vol_id /dev/sda1 | grep UUID
ID_FS_UUID=4a6aed11-42dd-4c82-81ce-8f469e93f210
root@grml # eval $(/lib/udev/vol_id /dev/sda1 | grep UUID)
root@grml # ls -la /dev/disk/by-uuid/$ID_FS_UUID
lrwxrwxrwx 1 root root 10 Aug 10 11:01 /dev/disk/by-uuid/4a6aed11-42dd-4c82-81ce-8f469e93f210 -> ../../sda1

Now we know the UUID and boot the system via root=UUID=… instead of a root=/dev/sda-entry:

title           Debian Etch, kernel 2.6.15-1-686 (on /dev/sda1)
root            (hd0,0)
kernel          /boot/vmlinuz-2.6.15-1-686 root=UUID=4a6aed11-42dd-4c82-81ce-8f469e93f210 ro
initrd          /boot/initrd.img-2.6.15-1-686

Finally do not forget to adjust /etc/fstab as well for all entries:

UUID=e0164f78-9821-4eaf-bda7-1fd9b43a6f06 /     ext3  defaults,errors=remount-ro 0 1
UUID=4a6aed11-42dd-4c82-81ce-8f469e93f210 /home ext3  defaults                   0 0
UUID=0e88f32f-fb98-4279-b3bc-8edfc2046b5d none  swap  sw                         0 0

mika

Stable root device (AKA UUID) 

# xfs_admin -L test /dev/hda1
writing all SBs
new label = "test"
# findfs LABEL=test
/dev/hda1

documented on: August 13th, 2006 at 23:53, Michael Gebetsroither

locating boot scripts (multiplatform install) - how? 

Newsgroups: comp.os.linux.setup
Date: Wed, 27 Nov 2002 00:06:58 GMT
> I'm trying to find a generic way to put my boot script in the right
> place.  I've read & googled but must be missing something.  How does
> init know where to find the boot scripts?
>
> E.g.
> - on Debian systems, the initialization script is /etc/init.d/rcS,
> - on Red Hat, /etc/rc.d/rc.sysinit.
> - on SuSE older versions /sbin/init.d/rc newer /etc/init.d/rc  (??)
> - on Slackware (BSD-based init) /etc/rc.d/rc.S

I'll add Mandrake /etc/rc.d/init.d with links from the /etc/rc.d/rcX.d directories

locating boot scripts (multiplatform install) - how? 

> I'm trying to find a generic way to put my boot script in the right
> place.  I've read & googled but must be missing something.  How does
> init know where to find the boot scripts?

"man init" describes the operation of init in detail. Most of the magic begins in /etc/inittab file. There are no doubt several incompatibilites between different Linux distributions regarding the actions launched by /etc/inittab. However, many popular Linux distributions are aiming to produce distributions that conform to the Linux Standard Base. So you may want to browse through the following pages, for example:

http://www.linuxbase.org/spec/gLSB/gLSB/sysinit.html

CrayzeeWulf

reordering boot processes 

Newsgroups: comp.os.linux.setup
>  I need to reconfigure my boot order for processes to place pcmcia
> before ppp0. Which file do I edit?
/etc/modules/default

reordering boot processes 

In debian, it is:

$ dir /etc/modules*
-rw-r--r--    1 root     root          424 May  8 09:47 /etc/modules
-rw-r--r--    1 root     root         3000 May 28 07:20 /etc/modules.conf

Booting on iso image 

Newsgroups: comp.os.linux.misc,alt.os.linux
Date: 20 Dec 2002 14:28:46 GMT
> i just downloaded  a ISO cd image for knoppix linux system.
> This image is bootable, but i dont have any CD burner.  so i
> want to know if there is any software which will let us boot
> on an ISO cd image from a hard disk.

VMWare can do this. You tell it to use an iso file as a CD drive and it will boot from that image into a fully operable Knoppix system. VMWare costs $$$$ though.

Lee J. Moore

Booting on iso image 

> All sugesstions, internet links,  are welcome

Do you have another Linux box somewhere on a LAN?

If so then you could mount the file (using loopback support) on that box and export it as NFS (the linux filesharing protocol filesystem).

Then recompile the KNOPPIX kernel to support NFS root_fs boots, which basically allows you to mount the root '/' filesystem from a NFS share. Point this mount to the NFS share location.

Now re-write this new kernel and boot options to the files on a boot floppy which you will need to make from the boot images on the CD (in /KNOPPIX/)

Boot from the floppy and try booting.

This may / maynot work, but would be interesting to see if it does.

Joe Fredrickson