[lfs-support] What Is "The" LFS Partition?

Bruce Dubbs bruce.dubbs at gmail.com
Mon Nov 5 09:14:13 PST 2012

Feuerbacher, Alan wrote:
> Philippe Delavalade wrote:
>>> I read the man page for mke2fs and it's as clear as mud. And the
>>> LFS book is completely unclear about exactly what is going on.
>> The book suppose that you have some knowledge about linux and
>> partitions :-)
> Well I do have *some* knowledge. It's just a matter of how much. :-)
> Seriously, I'm doing this in order to learn about all this stuff.
>> And the man about mke2fs is not so unclear, as I can remember.
> It is to me. I'll have to think a lot more about what you and Bruce
> have told me, in terms of the mke2fs man page, and try to understand
> what I'm missing.
>>> Are you saying that I have to run mke2fs for EACH of the devices
>> /dev/sda1, /dev/sda2 and so forth?
>> You'll have to do it for /dev/sda6 and for /dev/sda7 ; on sda2, I
>> think you plane to install your home and that can wait ; for
>> /dev/sda1 I think you can wait still the installation of the
>> bootloader ; and /dev/sda5 is the swap, you'll see what to do with
>> it at the end of your current section.
> My plan WAS to have /dev/sda1 as the /boot partition, and the rest as
> whatever fdisk forces you to have. After some experimentation and
> absorbing the material in the LFS book, I hit on this:
> /dev/sda1     /boot    500M
 > /dev/sda2     extended partition containing everything else
> /dev/sda5     swap 32G (I have 16G of RAM)
 > /dev/sda6     /usr /dev/sda7
 > /opt and so forth, following the LFS book.

/boot of 500M is a little large.  I normally use 100M, but it probably 
doesn't matter.

For a first build, do not use a separate /usr.  Don't open yourself to 
potential problems until you understand more.

You do not need 32G of swap.  That 2x RAM rule is obsolete.


I suggest 2G swap.  You can always add more later.

If you are going to use a MSDOS partition table, why skip 2 parimary 
partitions?  It really doesn't matter that much though.

> Questions:
> Why would I NOT use mke2fs immediately to make filesystems on sda1,
> sda2 and sda5? I want to know enough to really understand what is
> going on sufficiently that I could teach it to my grandmother. :-)

You can do it whenever you like.

> Why would I wait until the installation of the bootloader? Wait for
> what?

I think the idea was to put off the decision until you actually needed 
to install something on the partition.  It really doesn't matter though.

>> Anyway, there is certainly a swap partition on your host system.
> Yes, but what does that have to do with the LFS system?

All systems can share the same swap space.  It actually makes some sense 
to have the swap partition on a different drive for marginally improved 
performance (but you really don't want to use swap anyway, just have it 
available if absolutely needed).

> Ok, then: how does one get that information from the man page on
> mke2fs?

Man pages are not meant as a primary learning tool.  They are supposed 
to be quick references for options, etc.

"mke2fs  is  used  to create an ext2, ext3, or ext4 filesystem, usually 
in a disk partition."

What part do you not understand?

> OK, but the LFS book clearly says that every partition will be ext3.

In Section 3.3 it says "Instructions for creating other file systems can 
be found at 
  ext3 is just used as the primary example.

If you don't know why you want to deviate from the book, don't.

   -- Bruce

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