Multiple profiles

Multiple profiles

[Gregory Giguashvili]

Hello,

I wonder if somebody is familiar with the way to create multiple hardware
configurations (profiles) on Linux? This is required, for instance, when
booting laptop not connected to the network.

Thanks in advance,
Giga
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Gregory Giguashvili
Senior Software Engineer
Email: gregoryg@ParadigmGeo.com
Tel: 972-9-9709379 Fax: 972-3-9709337
Paradigm Geophysical Ltd.
http://www.math.tau.ac.il/~gregoryg

Re: Multiple profiles

[David Schwartz]

On Thu, 27 Jun 2002 11:30:03 +0200, Gregory Giguashvili wrote:

>Hello,
>
>I wonder if somebody is familiar with the way to create multiple hardware
>configurations (profiles) on Linux? This is required, for instance, when
>booting laptop not connected to the network.
>
>Thanks in advance,
>Giga

	There is no way to create multiple profiles on Linux. But there may be a way 
on particular distributions or installations. Multiple hardware 
configurations mostly have to do with:

	1) What kernel gets loaded.

	2) What initial root disk is used.

	3) What modules are loaded.

	4) What configuration scripts are run, how they setup hardware during the 
bootup process, and so on.

	All of these things are handled by things that vary from Linux machine to 
Linux machine. How you choose which kernel to boot depends upon your boot 
manager. How your configuration scripts work depends upon how those scripts 
are constructed.

	DS

Re: Multiple profiles

[Oliver.Neukum]

On Thu, 27 Jun 2002, David Schwartz wrote:

> 	There is no way to create multiple profiles on Linux. But there may be a way

Actually there is. We call them runlevels. init seems to be pretty
standard on Linux systems.

	Regards
		Oliver

Re: Multiple profiles

[David Schwartz]

On Thu, 27 Jun 2002 14:22:07 +0200 (MET DST), 
Oliver.Neukum@lrz.uni-muenchen.de wrote:

>On Thu, 27 Jun 2002, David Schwartz wrote:
>
>>    There is no way to create multiple profiles on Linux. But there may be 
>>a
>>way

>Actually there is. We call them runlevels. init seems to be pretty
>standard on Linux systems.

	True, though runlevels don't allow you to change the kernel you're using, 
its command line, or the initrd. In addition, many distributions' preferred 
means of creating profiles is not by means of runlevels.

	DS

Re: Multiple profiles

[Richard B. Johnson]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1080 bytes --]

On Thu, 27 Jun 2002, David Schwartz wrote:

> 
> On Thu, 27 Jun 2002 14:22:07 +0200 (MET DST), 
> Oliver.Neukum@lrz.uni-muenchen.de wrote:
> 
> >On Thu, 27 Jun 2002, David Schwartz wrote:
> >
> >>    There is no way to create multiple profiles on Linux. But there may be 
> >> a way
> 
> >Actually there is. We call them runlevels. init seems to be pretty
> >standard on Linux systems.
> 
> 	True, though runlevels don't allow you to change the kernel you're
>  using, 
> its command line, or the initrd. In addition, many distributions' preferred 
> means of creating profiles is not by means of runlevels.
> 

You can boot different 'profiles' like the attached script shows. With
`initrd`, you can even query the user after initial boot, about what
'profile' you might want. It can then set up whatever you want, then
in a final heave, do `exec /sbin/init auto` and you are running the
startup files (the profile) that you specified.

Cheers,
Dick Johnson

Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).

                 Windows-2000/Professional isn't.

[-- Attachment #2: Type: TEXT/PLAIN, Size: 3869 bytes --]

#!/bin/bash
#
#	This installs the kernel on a system that requires an initial
#	RAM Disk and with an initial SCSI driver.
#

export VER=$1
RAMDISK_DEVICE=/tmp/RAM.DATA
RAMDISK_MOUNT=/tmp/Ramdisk
DISKSIZE=1800
SYS=/usr/src/linux-${VER}/arch/i386/boot/bzImage
MAP=/usr/src/linux-${VER}/System.map
if [ "$1" = "" ] ;
   then
       echo "Usage:"
       echo "make_ramdisk <version>"
       exit 1
fi
if [ ! -f ${SYS} ] ;
   then
    echo "File not found, ${SYS}"
    exit 1
fi
if [ ! -f ${MAP} ] ;
   then
    echo "File not found, ${MAP}"
    exit 1
fi
if ! depmod -a ${VER} ;
   then
      echo "This won't work!  There are some unresolved symbols."
      exit 1
fi
umount /initrd 2>/dev/null
umount ${RAMDISK_DEVICE} 2>/dev/null
umount ${RAMDISK_MOUNT}  2>/dev/null
mkdir  ${RAMDISK_MOUNT}  2>/dev/null
dd if=/dev/zero of=${RAMDISK_DEVICE} bs=1k count=${DISKSIZE}
mke2fs -Fq ${RAMDISK_DEVICE} ${DISKSIZE}
mount -o loop ${RAMDISK_DEVICE} ${RAMDISK_MOUNT}
rmdir ${RAMDISK_MOUNT}/lost+found 
mkdir ${RAMDISK_MOUNT}/dev
mkdir ${RAMDISK_MOUNT}/etc
mkdir ${RAMDISK_MOUNT}/lib
mkdir ${RAMDISK_MOUNT}/bin
mkdir ${RAMDISK_MOUNT}/sbin
mknod ${RAMDISK_MOUNT}/dev/null   c 1 3
mknod ${RAMDISK_MOUNT}/dev/ram0   b 1 0 
mknod ${RAMDISK_MOUNT}/dev/ram1   b 1 1
mknod ${RAMDISK_MOUNT}/dev/sr0    b 11 0 
mknod ${RAMDISK_MOUNT}/dev/scd0   b 11 0 
mknod ${RAMDISK_MOUNT}/dev/tty0   c 4 0
mknod ${RAMDISK_MOUNT}/dev/tty1   c 4 1
mknod ${RAMDISK_MOUNT}/dev/tty2   c 4 2
mknod ${RAMDISK_MOUNT}/dev/tty3   c 4 3
mknod ${RAMDISK_MOUNT}/dev/tty4   c 4 4
ln -s /dev/tty0 ${RAMDISK_MOUNT}/dev/systty
ln -s /dev/tty0 ${RAMDISK_MOUNT}/dev/console
ln -s /dev/ram1 ${RAMDISK_MOUNT}/dev/ram
ln -s /dev/sr0  ${RAMDISK_MOUNT}/dev/cdrom
ln -s /         ${RAMDISK_MOUNT}/dev/root
cp /bin/ash.static ${RAMDISK_MOUNT}/bin/sh
cp /sbin/insmod.static ${RAMDISK_MOUNT}/bin/insmod
cat >/tmp/fake.c << EOF
main(){return 0;}
EOF
gcc -o ${RAMDISK_MOUNT}/sbin/modprobe /tmp/fake.c --static
rm -f /tmp/fake.c
#
# Add modules to this list in the exact order you need them installed
#
modules="scsi_mod.o sd_mod.o BusLogic.o cdrom.o sr_mod.o loop.o isofs.o"
#
echo "#!/bin/sh"   >${RAMDISK_MOUNT}/linuxrc
for x in $modules ; do
  cp `find /lib/modules/${VER} -name "$x"` ${RAMDISK_MOUNT}/lib
  echo "/bin/insmod /lib/$x" >>${RAMDISK_MOUNT}/linuxrc
done
chmod +x ${RAMDISK_MOUNT}/linuxrc
df ${RAMDISK_MOUNT}
sync
umount ${RAMDISK_MOUNT}
rmdir  ${RAMDISK_MOUNT} 
dd if=${RAMDISK_DEVICE} bs=1k count=${DISKSIZE} | gzip >/boot/initrd-${VER}
rm -f ${RAMDISK_DEVICE}
cp ${SYS} /boot/vmlinuz-${VER}
cp ${MAP} /boot/System.map-${VER}
rm -rf /boot/System.map
ln -s /boot/System.map-${VER} /boot/System.map
psupdate
#
echo >/boot/message
echo "    Booting Linux version ${VER}"                  >>/boot/message
echo "    Hit tab key to see alternatives"               >>/boot/message
echo "    This machine will self-destruct in 15 seconds" >>/boot/message
echo >>/boot/message
#
lilo -C - <<EOF
#
#  Lilo boot-configuration script.
#
boot = /dev/sda
message = /boot/message
compact
delay = 15	# optional, for systems that boot very quickly
vga = normal	# force sane state

image = /boot/vmlinuz-${VER}
  initrd = /boot/initrd-${VER}
  root  = current
  label = new 
  append = "nmi_watchdog=0"

image = /boot/vmlinuz-${VER}
  initrd = /boot/initrd-${VER}
  root  = /dev/scd0 
  label = cdrom 

image = /vmlinuz
 root = current
 label = linux

image = /boot/vmlinuz-${VER}
  initrd = /boot/initrd-${VER}
  root  = /dev/sdc3 
  label = maint 

image = /boot/vmlinuz-${VER}
  initrd = /boot/initrd-${VER}
  root  = /dev/sdc1 
  label = maint-su
  append="init=/bin/bash" 

image = /vmlinuz.old
  root = current
  label = linux_old

other = /dev/sda1
  table = /dev/sda
  label = dos
EOF

RE: Multiple profiles

[Jesse Pollard]

---------  Received message begins Here  ---------

> 
> >I wonder if somebody is familiar with the way to create 
> >multiple hardware configurations (profiles) on Linux? 
> 
> Sorry for not being clear enough. I got several replies saying that this is
> not a kernel list question, I suppose because of the example with the
> network. In reality, this problem is much broader...
> 
> One might think of external devices (tapes, scaners, disks, etc.) constanly
> being moved from machine to machine. I understand I can twist /etc/init.d/*
> to support all the configurations. However, I don't see a reason why it
> cannot be the responsibility of Linux kernel to "see" different hardware
> configurations on boot.

Now you got specific.

Most tapes/scanners/disks that are removable/detachable are using the USB.

If that is the case, then yes - they can be handled automatically.

You do have to setup the USB daemon and drivers. Once configured they should
be connected automatically. Depending on the type of disk (hard disk,
filesystem type, access authorizations) you run into additional complications.

Not everything SHOULD be automatically done. For instance - overriding
authorizations on a disk drive can allow a workstation user to violate the
security policy established for the disk drive. The same can be said for
a tape or floppy. Such policies are NOT implementable inside the kernel
(at least not portably).

This is one reason an automatic mount is not necessarily valid. That policy
cannot be supported (or even identified) by the kernel.

Scanners and printers however, are more policy neutral - they don't inherently
store data that is policy controlled. At least not in the US. These devices
are usually immediately available after connection. (Though I'm still working
on getting my HP G55 scanner/printer working - it is recognized by the USB
subsystem as soon as it is attached).

I believe in other countries scanners are required to be able to label the data
being scanned and/or printed to identify the source of the data (doesn't prevent
tampering, but it is still a policy).

> >From the replies I got, I understand that Linux kernel doesn't provide such
> functionality. That's all I wanted to know.


-------------------------------------------------------------------------
Jesse I Pollard, II
Email: pollard@navo.hpc.mil

Any opinions expressed are solely my own.

RE: Multiple profiles

[Gregory Giguashvili]

>I wonder if somebody is familiar with the way to create 
>multiple hardware configurations (profiles) on Linux? 

Sorry for not being clear enough. I got several replies saying that this is
not a kernel list question, I suppose because of the example with the
network. In reality, this problem is much broader...

One might think of external devices (tapes, scaners, disks, etc.) constanly
being moved from machine to machine. I understand I can twist /etc/init.d/*
to support all the configurations. However, I don't see a reason why it
cannot be the responsibility of Linux kernel to "see" different hardware
configurations on boot.

>From the replies I got, I understand that Linux kernel doesn't provide such
functionality. That's all I wanted to know.

Best,
Giga
P.S. BTW, I needed this for RH distribution.

Re: Multiple profiles

[Brad Hards]

On Thu, 27 Jun 2002 23:19, Gregory Giguashvili wrote:
> One might think of external devices (tapes, scaners, disks, etc.) constanly
> being moved from machine to machine. I understand I can twist /etc/init.d/*
> to support all the configurations. However, I don't see a reason why it
> cannot be the responsibility of Linux kernel to "see" different hardware
> configurations on boot.
We can do this, for some device types. Not just for boot, but for hotplug type 
devices as well. The kernel option is CONFIG_HOTPLUG, and it signals 
userspace to describe what went on.

It is not appropriate for the kernel to decide what goes on (eg, if you attach 
a USB scanner, whether you'd like to load the necessary kernel modules, start 
up KDE and kooka, start a scan and save to /tmp/pr0n; or just ignore it for 
now because the scanner is noisy, and you'll start it running overnight from 
a cron job). So we make such policy decisions in userspace. This is normally 
some shell script run as /sbin/hotplug (although you can change the script 
name using a /proc interface). Sample scripts can be downloaded from 
http://linux-hotplug.sf.net, which has lots more documentation on this.

Does this address your concern?

Brad

-- 
http://conf.linux.org.au. 22-25Jan2003. Perth, Australia. Birds in Black.

RE: Multiple profiles

[Gregory Giguashvili]

>Most tapes/scanners/disks that are removable/detachable are 
>using the USB.
And what about non-removable non-USB devices? I understand I need to use
runlevels to achieve the goal...

Thanks,
Giga