I would tentatively suggest the following procedure for getting
Linux reliably on to your hard drive and being able to use all of it:
*) Check that the BIOS is the most up-to-date revision for your
motherboard -- you can check Intel Motherboards at:
http://developer.intel.com/design/motherbd/genbios.htm
*) Check that the BIOS is set to use LBA for this drive
*) Using the linux install disk, look at the boot-up messages. You should
get a message like:
hda: WDC AC36400L, 6149MB w/256kB Cache, CHS=784/255/63, UDMA
Check that that is sensible. During the Linux install process, use
linux-fdisk. Type p, and check how many cylinders, etc, etc, Linux thinks
the drive has. How you partition your drive depends on several things,
now: whether you want to use LILO, what linux-fdisk reports as the number
of cylinders and whether you want to risk changing this. You should
obtain, read and internally digest the HOWTO mentioned several times in
this thread while trying to work this. The problem is that the right
solution for a given system may depend on many things down to and
including the exact drive model, so a given person's experience may not be
of much help. I would suggest that at the very least you make the root
partition (where the kernel is based) <1024 cylinders, however big a
cylinder ends up being.
*) Then, try to install Linux. There's a reasonable chance things will
fail first time and you may have to scrub the whole disk, so make sure
that you can cope with this.
Consider the following possible scenario: you make sure you have LBA
turned on in the BIOS, you're installing RH Linux where the boot disk has
kernel 2.0.35 or better, and you wish to use LILO. Linux-fdisk reports
C/H/S to be (say) 30000/16/63. The first and safest recourse (although a
little inconvenient) in this case is to have your Linux root partition be
1023 cylinders (<504MB), and mount /usr, /var/tmp and /home on different
partitions (these don't have size restrictions). If, however, linux-fdisk
reports C/H/S to be (say) 1882/255/63, then you have more (safe) freedom
to specify the size of your root partition. If you have case one and you
*really* don't want to restrict your root partition to <504MB, then you
have two options, each with their own risks. You can either:
a) Make your root partition > 504MB anyway (and therefore *probably* be
unable to use LILO); or
b) change the C/H/S number for the disk. This in itself can be done in two
ways: you can either specify the parameters to the kernel as stated before
with the kernel option hd=cyls,heads,secs (when you first insert the
RH install disk, you will have a prompt. Hit <tab> to get the names of
possible kernels, and then (assuming the one you want is `linux'), type at
the prompt: linux hd=1882/255/63 (or whatever); or you can tell the disk
itself using the `expert' mode of linux-fdisk. Type `x' to get into expert
mode and `m' to see available commands.
Solution a) involves implications for using LILO since LILO is only able
to use the BIOS int13 technique for accessing disk info. b) involves
possible problems if you wish to have the disk easily accessible to Linux
and to (eg) Windows 95, 98 or NT -- see
http://linux-rep.fnal.gov/howtos/mini/Large-Disk-6.html, `Consequences'.
The only other thing to say is: write down your experiences and what you
find and try on your system -- even the mistakes, and mail them to this
list. That way we will be able to build up a list of cases and know better
how to deal with the many and various system configurations floating
around these days.
Anyway, I hope at least some of this is helpful, and best of luck with
your system. Let us know how it goes.
Cheers,
Chris.
On Mon, 30 Nov 1998, Stephen Bailey wrote:
>
> Hello. Thanks for all the quick replies. The memory issue
> seems simple. The disk is another matter.
>
> These large drives came as the only hard drives in the machines,
> and they had Windows 98 pre-installed. I presume that they were
> correctly formatted for ~14 Gb under Win98, although I have
> completely blown away any Microsoft products from these machines
> and can't verify that. But presuming that is true, it would
> seem that the BIOS should already be set to handle these large
> drives, yet the install fdisk didn't manage to format them very
> efficiently. If the BIOS is set correctly, should this happen
> automatically? For that matter, whether I'm using the BIOS or
> forcing C/H/S geometry, if large disk awareness doesn't happen
> automatically, how do I do this *during* the install, since
> Linux is going onto the large drive, the one and only
> drive in the box? As I recall from the install, I get shuffled
> off into fdisk before being able to specify anything special
> about the drive.
>
> Comments from experts would be appreciated. It seems that getting
> the BIOS to recognize large drives is the way to go, but I'm not
> sure what BIOS configuration I'm aiming for, and the HOWTO doesn't
> cover this case. And how to do this during an install is a mystery
> to me.
>
> Thanks.
>
> Stephen
>
>
>
>
>
>
>
>
-- Chris Green. HEP, Purdue University. CDF SVXII project. Based at Fermilab. MAIL greenc@fnal.gov; PHONE (630) 840-2308