Differences between revisions 6 and 7
Revision 6 as of 2008-04-06 18:16:34
Size: 8468
Editor: ?RobertEpprecht
Comment: fixed some errors, cosmetics
Revision 7 as of 2008-04-06 18:24:08
Size: 8463
Editor: ?RobertEpprecht
Comment: sorry some more mistakes sneaked in
Deletions are marked like this. Additions are marked like this.
Line 52: Line 52:
 1. Switch to vt2 (<ctr> + <alt> + <F2>)  1. Switch to console 2 (<ctr> + <alt> + <F2>)
Line 91: Line 91:
kernel /boot/vmlinuz-2.6.24-1-686 root=/dev/sd'''b'''1 ro single kernel /boot/vmlinuz-2.6.24-1-686 root=/dev/sdb1 ro single
Line 98: Line 98:
title Normal Boot (on /dev/sd'''a)'''1)
root (hd0,0)
title Normal Boot (on /dev/sda1)
root (hd1,0)
Line 113: Line 113:
 1. Now change back to vt1 (<ctr> + <alt> + <F1>) and let the installer reboot.  1. Now change back to console 1 (<ctr> + <alt> + <F1>) and let the installer reboot.
Line 115: Line 115:
 1. Now you can boot by pressing <esc> after power on, or if you boot from SD card you can change hd priority in the bios, and boot directly from the card.  1. You can boot by pressing <esc> after power on, or if you boot from SD card you can change hd priority in the bios, and boot directly from the card.

?TableOfContents

Introduction

The limited storage capability of the eeepc does not lend itself to keep multiple operating systems on the internal flash drive. A SD or SDHC card (which can stay forever in the built in card reader) or and usb stick can be a very convenient way to install another system and extended storage. This wiki page gives you a recipe how to do that. Use at your own risk!

This version of the page depends very much on the current versions of kernel, installer and the like and details will probably change in the future. Please edit, when things change.

Drawbacks

A system on an external flash medium can be convenient and very usable. There are some drawbacks, of course:

  • A system on a usb stick or SDHC card will be slower than on internal flash. Speed depends on internal eeepc hardware and the type of medium you use.
  • There is a real gotcha if you want to use suspend on such a system. Suspending can do damage to a filesystem mounted on on a usb device. This affects both usb sticks and the built in card reader. So *dont* use suspend on such a system. This might change in the future, but don´t count on it.
  • Installation is not difficult, but version device names keep changing in a very confusing way. If you are doing it the first time the following step by step instructions tries to avoid this confusion.

Installation on exteral flash drive: overview

  • The installation process is pretty much straightforward. The main difference to a normal installation is caused by the fact, that bootloader configuration (and sometimes /etc/fstab) are faulty and must be corrected. Device names do move around in a very confusing way. So here is a very detailed recipe, to avoid confusion and to show how to fix the faulty bits after running the installer. Sorry if it sounds overly complicated.
  • Precautions should be taken that you will not suspend such a system.

Installing on external flash drives

  1. Put the stick with the installer in the USB port on the left side.
  2. Press <esc> while booting and select the stick to boot from.

  3. Now put the SD or SDHC card into the built in reader. If you want to install to a usb stick put that one in the second usb port on the right side, the one that is closer to the display.
  4. Start installation until partitioning. Select manual partitioning.
  5. Spot the device you want to install to: The internal card reader is easy to find, the stick might show a brand label, size or something you can tell which stick is which. If you have no clue, then assume the installer is on /dev/sdb1 and the target stick on /dev/sdc1 (if you did put it in the USB ports I told you to).
  6. Write the device down (It's very likely to be /dev/sdc1 with the current installer).
  7. On a pristine stick or card you will see one fat partition, select and delete it.
  8. Now you will see free space. Select that, and create a new primary partition. Accept the default size to use the whole medium.
  9. Filesystem default ext3 is fine. Select mount option noatime
  10. I would set a volume label like eeeSDcard or eeeStick.
  11. Set the bootable flag
  12. Select 'Done setting up partition' and 'Finish partitioning and write changes to disk'.
  13. The installer thinks you should have a swap partition, but you can savely continue without. (There will be more warnings about missing swap).
  14. Now let the installer do it´s thing until it wants to write the GRUB bootloader. Stop now. Do *not* install the GRUB bootloader in the mbr.
  15. To install the bootloader on your external media you have to give the name of the device like the installer sees it during installation. So install it to the device (without partition number) you wrote down in the partitioner. Probably it will be /dev/sdc (*NOT* /dev/sdc1).

    You can double check this by switching to console 2 (press <ctr> + <alt> + <F2> and then <ret>) and use the mount command. It's the device where /target is mounted (without partition number).

    • You install GRUB on a device like /dev/sdc but this will show up as /dev/sdb when the system gets booted. Don't get confused, it *is* confusing. ;-)

  16. Continue until the installer wants to reboot, but don't do that yet. We must correct faulty disk and device names in /boot/grub/menu.lst and /etc/fstab first. You can do that inside the installer now, or you can decide to let the installer finish and mount the media somewhere else to fix things there before rebooting the eeepc. Next steps show how to do it from the installer.
  17. Switch to console 2 (<ctr> + <alt> + <F2>)

  18. The files show up mounted under /target. Make a security copy, something like
      cp -a /target/boot/grub/menu.lst /target/boot/grub/menu.lst.INSTALLER.back
      cp -a /target/etc/fstab /target/etc/fstab.INSTALLER.back
  19. Check and edit the drive letter in /etc/fstab. / should be mounted on /dev/sdb1 (not /dev/sdc1)

      nano /etc/fstab
    it should look like this:
      /dev/sdb1   /               ext3    noatime,errors=remount-ro   0  1

    Or even better, see http://www.cyrius.com/debian/nslu2/linux-on-flash.html

     /dev/sdb1       /               ext3    noatime,commit=120,errors=remount-ro  0  1
  20. Edit /boot/grub/menu.lst The external media should be on (hd0,0) Scrolldown until you see the entries for the installed system, something like

    ## ## End Default Options ##
    title           Debian GNU/Linux, kernel 2.6.24-1-686
    root            (hd2,0)
    kernel          /boot/vmlinuz-2.6.24-1-686 root=/dev/sdc1 ro quiet
    initrd          /boot/initrd.img-2.6.24-1-686
    ...
    ### END DEBIAN AUTOMAGIC KERNELS LIST

    Now change to ´root (hd0,0)´ and ´/dev/sdb1´. With my kernel version it looks like:

    title           Debian GNU/Linux, kernel 2.6.24-1-686
    root            (hd0,0)
    kernel          /boot/vmlinuz-2.6.24-1-686 root=/dev/sdb1 ro quiet
    initrd          /boot/initrd.img-2.6.24-1-686
    title           Debian GNU/Linux, kernel 2.6.24-1-686 (single-user mode)
    root            (hd0,0)
    kernel          /boot/vmlinuz-2.6.24-1-686 root=/dev/sdb1 ro single
    initrd          /boot/initrd.img-2.6.24-1-686

    The internal flash drive should be on (hd1,0) and /dev/sda(x) So for default xandros on internal drive you would edit the entries (farther down) entries to look something like:

    # This entry automatically added by the Debian installer for an existing
    # linux installation on /dev/sda1.
    title           Normal Boot (on /dev/sda1)
    root            (hd1,0)
    kernel          /boot/vmlinuz-2.6.21.4-eeepc quiet rw vga=785 irqpoll root=/dev/sda1
    initrd          /boot/initramfs-eeepc.img
    ...

    Now we must correct the entries for update-grub. Edit the device in the kernel options to /dev/sdb1

    # kopt=root=/dev/sdb1 ro

    and root to (hd0,0)

    # groot=(hd0,0)
  21. Now change back to console 1 (<ctr> + <alt> + <F1>) and let the installer reboot.

  22. You can boot by pressing <esc> after power on, or if you boot from SD card you can change hd priority in the bios, and boot directly from the card.

  23. Change the scripts under /etc/acpi so that they never do suspend. If you´re like me and have the habbit of saving your work very often or let your applications do that for you you can use my personal hack for this: I just do shutdown instead of suspend. I don´t even ask, who would answer the question when you just closed the lid? I have edited /etc/acpi/actions/suspend.sh
    # do nothing if package is removed
    [ -d /usr/share/doc/eeepc-acpi-scripts ] || exit 0
    if (runlevel | grep -q [06]) || (pidof '/sbin/shutdown' > /dev/null); then
        exit 0
    fi
    shutdown -h now

Booting external media

Common case

By pressing the <esc> key after power on you can select the device to boot from.

Booting from SDHC card

If you have your system on an SD card that you always leave in the slot, you might want to boot from it directly. The card must be in the slot for the bios to show this option. Press F2 after powering on to see the bios.

Go to the boot tab. If the card is in the slot you will find the option ´> Hard Disk Drives´ Change the card reader to be the first drive. (Attention: If you ever boot without the card the bios will silently revert this setting.)