Thanks to Fedora community; Installation & Disk Partitioning ISSUE
Marko Vojinovic
vvmarko at gmail.com
Thu Nov 3 11:44:21 UTC 2011
On Thursday 03 November 2011 07:33:33 Linux Tyro wrote:
> Inserted the CD in the CD-ROM (yes it was the first boot option).
> Everything was going on smooth but after some time I came to the windows
> where I have to do something regarding 'partitioning'. The CD, by default
> showed with the following output. It said me as followed:
> __________________________________
>
> -Delete partition /dev/sda5 (111.25 GB)
> -Create root volume /dev/sda6 (20.00 GB) with ext4
> -Create volume /dev/sda6 (91.25 GB) for /home with ext4
> -Use /dev/sda5 as swap
> -Set mount point of /dev/sda1 to /widows/c
> __________________________________
SuSE is telling you here what it is about to do. It wants to delete the big
Ubutu partition (/dev/sda5), and replace it with two partitions, one
(/dev/sda6) for / and the other (/dev/sda7, I believe you mistyped the "6"
above) for /home, all for SuSE (deleting Ubutnu in the process). In addition,
it intends to recreate /dev/sda5 to use it as the swap partition, and to
create a mount point for the Windows partition (/dev/sda1), so that you can
access your Windows files in the directory /windows/c from within SuSE.
I am not sure whether you retyped the /dev/sdaX numbers correctly, the /home
entry is probably /dev/sda7.
There is nothing wrong with this setup, and IMHO having separate / and /home
is better than what Ubuntu installed (just a single big / and no separate
/home). I recommend that you accept this setup.
> I continued with this (the above) default scheme which it took and didn't
> click to 'edit the partition'. Finally arrived at the page where the
> summary of what the distro is going to do in finally (for installation). At
> this page/step was written in red, the following message:
> __________________________________
>
> "The boot loader is installed on a partition that doesn't lie entirely
> below 128 GB. The system might not boot is BIOS support only lba24 (result
> is error 18 during install grub MBR)."
> __________________________________
>
> What does it ('the installation process') want to say?
Ok, you need to learn a bit or two about booting a PC. Dual-booting is a
nontrivial thing to setup, so you need to be aware of what is actually going
on inside.
You want to read about that on
http://en.wikipedia.org/wiki/Booting#Boot_sequence_on_standard_PC_.28IBM-
PC_compatible.29
When you turn on a computer, the very first thing that happens is that the
motherboard oscillator clock stats ticking. This invokes a piece of hardware
that sends a reset signal to the processor. The processor than resets itself
and starts executing commands from a fixed predetermined position in memory.
This is where the bios resides.
The bios gets loaded, does a bunch of initialization and self-testing stuff,
and eventually looks up the MBR (master boot record) of your hard disk, to
load an operating system.
The MBR is located at the very beginning of the hard drive, and is 512 bytes
long. It contains the partition table of the disk, and a "stage 1" bootloader
--- a small piece of code which knows "where to look" for an operating system
to load. Now comes the catch --- this piece of code is very size-constrained,
so it relies on bios routines to access the remainder of the hard disk. The
bios, however, may be old, and not have built-in support to access the whole
space of the 250 GB hard drive. Or maybe it can. It depends on your particular
bios, and the SuSE installation cannot check whether bios is capable of this
or not.
In the end, you get the warning that the "stage 2" bootloader, which is to be
positioned at the beginning of the /dev/sda6 partition, might be out of reach
of bios. If it is, your system would fail to boot the SuSE installation.
Windows would be bootable no problem, because its "stage2" bootloader is at
the beginning of the /dev/sda1, which is on the "near end" of the hard drive,
and thus certainly within the reach of bios.
Of course, once the OS gets booted, it can see the whole disk with no
problems, because the OS kernel (both the Windows and Linux one) is much more
powerful than the bios, and does not rely on the bios to access the disk.
You have two options:
(1) To look up the docs/specifications of your bios version on the Internet,
and read wheter or not it supports large hard drives (and how large).
(2) To experiment --- proceed with the installation of SuSE and hope that bios
can access the disk that far. My bet is that it can, since Ubuntu had no
problems booting from the same place on the disk. ;-)
> Now the partition table (which came BY DEFAULT, at the step at which the
> above error (in red) came) was as follows:
> __________________________________
>
> /dev/sda 232.89 GB
> /dev/sda1 116.88 GB HPFS/NTFS NTFS /windows/c
> /dev/sda1 116.01 GB Extended
> /dev/sad5 4.75 GB Linux swap Swap Swap
> /dev/sda6 20.00 GB F Linux native Ext4 /
> /dev/sda7 91.25 GB F Linux native Ext4 /home
> __________________________________
>
> First line: Well, /dev/sda is the whole of hard disk and its capacity is
> 232.89 GB. Its well understood. But when I bought, the vendor told me the
> capacity of 250 GB, so remaining (250-232.89) GB=17.11 GB are where, I
> don't know.
Q: How many meters are there in a kilometer?
A: 1024 --- ask any programmer! :-)
You want to read about that on
http://en.wikipedia.org/wiki/Byte#Unit_multiples
When a disk manufacturer says 1GB, they typically mean 1 000 000 000 bytes,
which is 1000^3. When an OS says 1 GB (or more precisely 1GiB), it means
1 073 741 824 bytes, which is 1024^3. Hence the difference.
Also, some of the space on the disk is used up for filesystem data (and its
backups), some of it may be reserved for root (for administration purposes),
etc.
> Second line: /dev/sda1 is the Windows partition, and I guess it is taking
> number '1' since it is the default boot option...? It has been formated by
> NTFS file system as shown clearly.
It takes a number 1 because it takes the first position on the disk, physically
speaking (it's on the "near end" of the disk). Boot order has nothing to do
with this.
> Third line: /dev/sda1 extended? Is it windows only? If yes, why its size is
> 116.01 GB? and not 116.88 GB (which is in the line just above it). What
> does it mean?
I believe that wolud be /dev/sda2, rather than /dev/sda1. Please be careful
when retyping these things. :-)
You want to read about that on
http://en.wikipedia.org/wiki/Disk_partitioning#PC_partition_types
In short, there can be at most *four* primary partitions on a disk. If there
is need for more, one of these four is declared as "extended", and is chopped
up into a larger number of "logical" partitions. In your case, there is one
primary partition (/dev/sda1), and another primary partition (/dev/sda2) which
is declared extended, and contains several other logical partitions inside it.
Its total size is 116.01 GB, which is the space divided between swap, / and
/home. The other primary partition, /dev/sda1, is used by Windows (the C:
drive), and it is 116.88 GB in size.
The 116 for sda2 has nothing to do with the 116 for sda1, it's a coincindence
that they are almost equal in size, dividing your 250 GB disk in two almost
equal pieces. It could have been different, depending on the size of the
Windows partition.
> Fourth line: /dev/sda5 Okay Linux swap, understood and it is separate
> partition. I don't know where /dev/sda2, /dev/sda3, /dev/sda4 have gone??
>
> >From '1' it has jumped to -->> '5'...!
The dev/sda2 is the extended partition, and /dev/sda3 and /dev/sda4 would be
3rd and 4th primary partitions, if you had them. But you don't --- you have
only two primary partitions, sda1 and sda2, the latter being declared
extended. It contains several logical partitions, which are numbered sda5 and
onwards.
Trust me, it would be an even bigger mess if logical and primary partitions
were mixed up in numbering. Don't worry about it.
Incidentally, in principle you could customize your partition setup, and
instead set up four primary partitions, like this:
/dev/sda1 for Windows
/dev/sda2 for Linux /
/dev/sda3 for Linux /home
/dev/sda4 for Linux swap
That way all partitions would be primary, and there would be no extended
partition. However, if you later choose to divide one of those partitions into
two or more, you're out of luck --- you would have to back up the whole
partition, delete it and create an extended one in its place.
> Fifth line: /dev/sda6 is the root, since at the last symbol '/' is coming
> and again its a separate partition. But why it is calling Linux native? And
> why there is coming a 'F' written just after 20.00 GB, what is it
> representing?
You want to read more about that on
http://en.wikipedia.org/wiki/Filesystem#File_systems_and_operating_systems
It is called Linux native because the filesystem which is to be put on it is
ext4, rather than fat32 or ntfs, which Windows could use. The "F" symbol is
the mark that this partition is going to be formatted during the install,
deleting all previous data that may be on it (the Ubuntu OS, in your case).
> Sixth line: /dev/sda7 ok its /home (written at the last), but it is also
> 'Linux native' and again that 'F'.
Same as above.
> On the same stage (on which the partition table and the error in red was
> being displayed), I had one more thing interesting, it is as follows. It
> was under the heading 'Change Location':-
> __________________________________
>
> -Boot from MBR is disabled (enable)
> -Boot from "/" partition is disabled (enable)
> __________________________________
>
> I don't know WHY to enable any one of the above options or to enable both
> or to not touch............? And what does they mean (the above options).
The installer is asking you where you want to put the stage1 bootloader. There
can be several stage1 bootloaders on the disk, and they can be configured in a
"chain" --- the first one is always in MBR, and it redirects the booting to the
one that is on /dev/sda1, or the one on /dev/sda6, or elsewhere. That's how
you get to choose which OS to boot when you turn on the computer.
The SuSE can set up the MBR bootloader and/or the /dev/sda6 bootloader for
you, or skip it if some other OS is already using the MBR (that would be
Ubuntu, in your case).
Since you are going to delete Ubuntu, its bootloader in MBR will fail to work.
You want to let SuSE set up the MBR, and leave the / partition alone. SuSE
will take care of itself, and it will take care of Windows via chainloading
its bootloader on /dev/sda1. You *don't* want to leave Ubuntu's bootloader in
the MBR.
If you instead wanted to install SuSE alongside Windows *and* Ubuntu, you
would have more than one way to answer this question (and it could get quite
complicated). When setting up multiboot environments, you *always* want to be
aware of what you are doing when configuring the bootloader(s), and *need* to
learn and understand how it all works together. One wrong choice can render
the whole machine nonbootable. The dual-boot is the simplest of these
configurations, but still you need to have a good idea what you are doing. :-)
Btw, unwillingness to learn these things is one of the reasons why some people
opt to using virtual machines instead of multiboot environments (of course,
this is not the only reason, there are other pro's and con's...).
> If any one can elaborate in detail all this above mentioned points, I would
> be really be thankful to. IF anything better could be done, please
> elucidate regarding the partitioning given above.
Given that you are a beginner, I can suggest to keep / and /home separated,
with additional partitions for swap and Windows. Choose / to be 20GB, choose
swap to be 2GB (it can't hurt, since you have 2GB of physical RAM), and choose
/home to take up all space that remains on the disk, since that is where all
your user data will reside (documents, music, movies, etc.... you want it to
be big enough).
Later on, if you choose to reinstall Linux, you just format the / partition,
and point the new installation to use the old /home (without formatting it),
thus keeping all your data, customizations etc. across installs. There can be
some nontrivial gotcha's there, but in general it will work better than just
having one big / partititon.
HTH, :-)
Marko
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