GRUB loading, Error 18

Asked by jt on 2009-08-22

After installing Ubuntu 9.04 alongside Windows XP, my computer is stuck with the following opening message:
  GRUB Loading stage1.5.

  GRUB loading, please wait...
  Error 18

I've booted from the CD and given the output to these commands:
  free -m:
    Mem: total 181, used 178, free 2, shared 0, buffers 4, cached 57
    -/+ buffers/cache: used 116, free 64
    Swap: total 1088, used 29, free 1058

  sudo fdisk -l:
    Disk /dev/sda: 163.9 GB, 255 heads, 63 sectors/track, 19929 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Disk identifier: 0x37273726

       Device Boot Start End Blocks Id System
    /dev/sda1 * 79 9257 73730317+ c W95 FAT32 (LBA)
    /dev/sda2 9795 19929 81409387+ 5 Extended
    /dev/sda3 1 13 104391 83 Linux
    /dev/sda4 14 78 522112+ 82 Linux swap / Solaris
    /dev/sda5 9795 19861 80863146 83 Linux
    /dev/sda6 19862 19929 546178+ 82 Linux swap / Solaris

Thanks in advance for your help.

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Simos Xenitellis  (simosx) said : #1

"Error 18" is described at

The gist is that the BIOS of your computer is not in a position to access the start of your Linux partition that has the /boot directory.
In your case, the relevant partition is probably /dev/sda3 (at position 73GB), a dedicated partition for /boot.

Reading the above link, it appears that your computer may have a 8GB limitation. That is, you would need to move /dev/sda3 to come to the start of the hard disk. Can this be done with GParted from the installation disk?

You can also check if your manufacturer provides an updated BIOS that does not have a BIOS access limitation.

Tom (tom6) said : #2

Hi :)

Yes Simos is right there.

Updating the bios can be daunting and could cause problems if your machine gets stuck halfway through. i would avoid it unless you are either quite experienced with this type of thing or else don't care if the machine gets trashed. It's unusual for it to go that wrong but does sometimes happen.

I have been trying to re-write/heavily-edit the LiveCd guide
so any feedback on that guide would be most welcome and if you can add screenshots that would be even better, i could re-arrange them later. I'm not totally happy with it at the moment but i think it's getting there.

Anyway, from a LiveCd session go up to the top taskbar and click on

System - Administration - Partition Editor

this should allow you to right-click on sda6 to do "SwapOff" and then right-click again should let you delete it. Hopefully you haven't yet used Ubuntu on that drive yet so deleting sda5 after "umount"ing it should be safe, without losing data? If so then deleting sda2 (the Extended Partition) and all the other linux partitions should be quite easy allowing us a fresh start. If this isn't possible then we could easily work-around what's there as it doesn't really seem to be as bad as it might look.

Yes we need a 100Mb ext3 (or ext4) Primary Partition at the front of the hard-drive, where sda3 is at the moment - so that's fine. This will be the /boot partition to solve the bios/grub18 issue.

Also the linux-swap being over 2xRam as a Primary Partition immediately after the /boot partition and just before the Windows partition is brilliant to maximise performance on this machine. Read/writes are faster at the front of most drives so having a swap that gets used a lot right there so near the start of the drive is perfect. It looks like sda4 is a little large but that's great because it allows for potential ram upgrades in the future. It looks like your machine currently has 192Mb or 256Mb of ram with some of that taken away for the graphics card to use. Presumably this machine is a laptop? Anyway, again you've set it up perfectly.

The only reason for deleting and re-creating sda4, sda3 & sda2 is to get the numbering a little tidier but it's really not needed. The main thing is to have a look at what values the Partition Editor (GPartEd probably) gives us for the sizes of the partitions. Please let us know how this goes

Regards from
Tom :)

Best Tom (tom6) said : #3

Usually you have to delete higher sda numbers before it lets you mess around with lower numbers, not always true but that is quite often the way. Note that "Swap Off" is the linux-swap's equivalent of "umount" and a partition can't be deleted if it's being used (hopefully).

jt (jwtucker) said : #4

I have sda2, sda5, and sda6 deleted. This was a hangup for me earlier. Now I'm set with this:

  /dev/sda1 * 79 9257 73730317+ c W95 FAT32 (LBA)
  /dev/sda3 1 13 104391 83 Linux
  /dev/sda4 14 78 522112+ 82 Linux swap / Solaris

The computer is an older desktop with 256 Mb or ram (if memory serves me correct). Thanks for your help.

jt (jwtucker) said : #5

Do I just try and reinstall Ubuntu to hard drive? Will it automatically go to the newly partitioned drives?

Tom (tom6) said : #6

Hi :)

We are still not quite set-up for installing a linux on this machine yet, nearly there tho. Also it seems that your ram is too small for the full Ubuntu and might even be too small for Xubuntu. However if Xp was working then Xubuntu should be fine.

The only differences between Ubuntu and Xubuntu really is that Xubuntu starts off blue instead of earthy tones and it lacks the full OpenOffice package although it does have alternatives and anyway OpenOffice can be installed quite easily.

Under-the-bonnet the colour difference is caused by Xubuntu using an Xfce Desktop Environment rather than the heavy Gnome one. Your machine thinks it only has 181Mb of ram and Xubuntu's stated minimum is 192Mb so you might need to consider 1 (or more) of 3 alternatives;

1. Install Xubuntu and then install an even lighter DE such as LxDE or perhaps just a lighter Window Manager such as OpenBox, BlackBox, Enlightenment (e16), Awesome, AeWm (tiled), FluxBox, IceWm, PekWm (tiled). LxDe, OpenBox & IceWm seem to be the most commonly used & i would avoid the tiled ones except on hand-held machines although

2. Buy/acquire some more Ram. It is tricky to buy the right sort of ram - it needs to be the right type and the right speed. I suspect that you need old-Sd-Ram rather than DDR or DDR2. Old-Sd-Ram has 2 notches along the copper-contacts side (don't touch the contacts!) whereas DDR and DDR2 have only 1 notch. The notches are to make sure the sticks are placed the right way around. About 100MHz seemed fairly typical for old-Sd-Ram but hopefully you might find your current sticks are labelled or you might find an old manual for your mbord online. Ram is very vulnerable to static shocks and is very easy to damage. Fortunately if you turn your machine off at the back and at the wall then the metal sides of the case should be earthed and so you should be able to get most of the invisible static charges off your fingers by rolling your fingers over the metal sides of your case taking care of the sharp edges. Ram sticks are usually held in place by little plastic levers at either end and spreading these out from the ram usually pushes the ram stick out a little way. When you push a ram stick back in you will find these little levers should close but may need a bit of encouragement.

3. A completely different distro might be better for this machine. There are many very well maintained ones aimed at this type of machine. Even though many have had very recent releases i would still consider trying out Wolvix Hunter 1.1.0 because it has the full OpenOffice included as standard, mepis might be great for your machine but if you can find your way to it's download section for it's testing branch then you might be very impressed with it's little brother antix. SliTaz is probably my 2nd favourite (Wolvix being 1st) but Puppy is even smaller and is often well liked even though it's compressed-linux and so is a lot more difficult to install new programs into
There are a huge range of other ones almost all available from DistroWatch homepage and i haven't tried them all but these are my 4 favourites so far. Try each as a LiveCd before considering installing, hopefully the first one you try will be fine so you wont need to try the others ;)

My favourite option is number 3, a small stack of the cheapest "Write once" or "record once" cds that are normally only available in stacks of 10 or more is probably the easiest way to quickly download and make a cd of a few and then reboot to try each distro in turn. It can be quite a fast hunt for a distro you like the feel of on your machine if you don't get bogged down in one distro for too long and it can really open your eyes to the variety available in gnu&linux.

For option 2 i would consider taking the machine to a shop, perhaps taking the hard-drive out and leaving that at home. A LiveCd only needs a cd/dvd-drive, it doesn't need a hard-drive. Booting up into a LiveCd session should get you to a command-line where the command "free -m" shows how much ram your machine can see.

Option 1 has a few alternatives such as installing the full Ubuntu and then trying out those various DEs and WMs but you would probably have to do this from a command-line via "recovery mode" whereas doing this from Xubuntu means you could probably use the normal Xfce desktop to install a few different ones and then "Switch User" or "Logoff" to get to the login screen which has an "Options" button you can use to try out different sessions with different DEs or WMs. Using Xubuntu would be much nicer and easier for this :)

Hopefully that gives plenty to consider!
Good luck and regards from
Tom :)

jt (jwtucker) said : #7

Before getting your last message, I was able to successfully install Ubuntu. I haven't used it to a great extent yet but can not boot to either XP or Ubuntu. I will try and upgrade the ram over time. Thanks to all and especially Tom for your time and effort in helping me get this sorted out.


jt (jwtucker) said : #8

Thanks Tom, that solved my question.

Tom (tom6) said : #9

Hi :)

Have you been able to test the new Ubuntu 10.04 before it gets officially released?
Trying it as a LiveCd or as an extra dual/multi-boot would be ideal. Developers and everyone are keen to try to iron out any problems before 10.04 gets officially released so you might find faster & more effective answers to your bug reports which would make 10.04 work better on your system for you

Thanks and regards from
Tom :)