[H-GEN] partition advice

[Robert Brockway]

On Mon, 22 Feb 1999, Paul Gearon wrote:

> > There is a whole theory of how to partition a disk :)
> 
> I was worried about this.  :^)

In practice I would be surprised if a well partitioned system was 2%
faster than a single partition.  One of the original reasons for
partitioning was to prevent fragmentation, but the ext2fs auto-defrags to
a certain extent anyway (as I'm sure the berlekley FFS does)

So people shouldn't panic about partitioning, but it is something worth
looking into.  On systems with limited HD space (say <400Mb these days) I
always juse use a partition for swap and a partition for / as otherwise
you end up filling the partitions too quickly.

> > SWAP The idea here is that as the drive head is flying 
> > between different
> >      partitions it shoudl pass over the swap partition and be 
> > able to read
> >      and write stuff there before going on its way.
> 
> This makes sense, but does it really happen this way?

Without checking the src code, I'm not really sure to tell you teh truth.
As I wrote this before it occured to me that I couldn't really say for
sure that this was what was occuring.  It would seem in a multi-tasking OS
that this should occur as a function of the multitasking.  ie when the
next timeslice occurs and a new proceess is run there is a good chance it
will need to load something from swap, and the head should be closer if
the swap is near the middle of the disk.
 
> It does, thanks.  Any recommendations on size though?

I try to keep / below 15Mb these days.  This is a good size unless you are
going to be keeping _alot_ of kernel images and module sets.  If you were
keeping such a large number then a /boot partition isn't always a bad
idea.  Some ppl try to keep it below 10Mb but I find that a bit squeezy.
This is all assuming that /tmp, /var, etc are all seperate partitions.

THe thing to remember about the / partition is that it is the one thing
that will really bring a unix system to its knees.  /home or /var or /usr
can have serious problems and the system will happily boot single user for
you to fix them.  If / has problems it can really barf.  Also / is the
only partition you can't unmount on a running system (for obvious reasons
:)

Statistically speaking, keep / small to minimise the problem of errors on
the root fs as they can really stuff with the system.

As for the sizes of other stuff.  Well, I learnt from experience that /usr
should be BIG.  Here is a copy of my df again to show you how I did it:

If you will have lots of users who will be using lots of mail, then
/var/spool should be big.  Not likely on a home system :)
Cheers,
	-Robert

blake[2:54pm]:/etc>df
Filesystem         1024-blocks  Used Available Capacity Mounted on
/dev/hda1              15856   11910     3116     79%   /
/dev/hda3            1189542  572591   555489     51%   /usr
/dev/hda4             726443  453013   235908     66%   /opt
/dev/hdb1              63885      18    60568      0%   /tmp
/dev/hdb2             127361   77719    43065     64%   /var
/dev/hdb3             634724  421569   180370     70%   /var/spool
/dev/hdb4             385923  236577   129413     65%   /home

Cheers,
	-Robert

--Robert Brockway B.Sc.  Email: robert at blake.humbug.org.au
                                robert at humbug.org.au, r.brockway at uq.net.au
			 WWW:   http://www.humbug.org.au/~robert
			 Founder of HUMBUG (http://www.humbug.org.au)


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