1 files changed, 176 insertions, 111 deletions

diff --git a/share/FAQ/DISKSPACE.FAQ b/share/FAQ/DISKSPACE.FAQ
index fe910b5b795d..e951a2297a58 100644
--- a/share/FAQ/DISKSPACE.FAQ
+++ b/share/FAQ/DISKSPACE.FAQ
@@ -1,46 +1,66 @@
-                    How to assign disk-space to FreeBSD.
+                    How to assign disk space to FreeBSD.
 
-1.  What is all this about
---------------------------
-After a general introduction, you will find explanations on what you need
-to do to assign space for FreeBSD on your disk(s).  The program documented
-herein is the "sysinstall" program which lives on the install-disks.
-
-1.1  What is the problem
-------------------------
-The problem is that disks are big.  So big that people don't want to use them
-in one piece.  With the latest disks being in the 9.0 Gbyte range (which for
-comparision is some six thousand floppydisks of the 1.4 Mb type) you cannot
-blame them.  It has always been this way, and most computers have some way
-of "slicing" the disks into more manageble chunks.
-
-1.2  A history-lesson
+1.0  Getting started.
 ---------------------
-MS-DOS, when hard-disk support was slammed on back in the late eighties, 
-didn't have this.  What it had was a way to install Xenix and MS-DOS
-on the same disk (MicroSoft were in the UNIX-business once, remember ?).
-In the first sector on the disk, was a piece of "boot-code" and a table
-with four entries.  Each of those entries pointed at a slice of the disk,
-and one of them was marked "active".  The machine would boot by reading
-the first sector into RAM, and jump to it.  The small piece of boot-code
-would look at the table and decide which OS was to be booted by looking
-for the "active" flag, load the first sector of that slice of the disk
-and jump to it.
-
-Later of course, they realized that disks could be bigger than the 32Mb
-the FAT-12 "filesystem" could handle, so they added a kludge:  They had
-two MSDOS slices, a "Primary" and a "Secondary".  The primary could still
-only be 32Mb, but the Secondary had no size limit.  And the trick was, it
-had another MBR in it, so now suddenly 5 slices could be availabel to 
-MS-DOS, later the made the Secondary MBR recursive, and thereby effectively
-avoided any number limit.  Of course you can still only have the 26 slices
-in MSDOS because they use "drive-letters".
-
-1.3  What FreeBSD does
+
+After a general introduction, you will find some explanation on what you need
+to do to assign space to FreeBSD on your disk(s).  This is done through
+the "sysinstall" program, which lives on the inital boot floppy.  Those
+already expert with PCs may wish to skip ahead to section 1.2, the rest of
+you may enjoy the brief history lesson.
+
+
+1.1  The ins and outs of allocating disk storage on your PC.
+------------------------------------------------------------
+
+Modern hard disk drives are now getting big enough that people don't want
+to allocate all of one to just one operating system anymore, especially
+given the increasing size of disk drives (the latest 9.0 Gbyte models holding
+the equivalent of some six thousand 1.44MB floppies!) and the virtual
+explosion of operating system options available for the PC.  To solve this
+problem, IBM came up with a scheme for "slicing" the disks into more manageble
+chunks, or partitions.  It works, but only just.  To better understand
+why, first a brief bit of history:
+
+MS-DOS, when hard disk support was unceremoniously grafted on back in the
+late eighties, didn't have such things.  What it had was a way to install
+Xenix and MS-DOS on the same disk (Remember when Microsoft were in the UNIX
+business?  A long time ago, to be sure!).
+
+In the first sector on the disk was a piece of "primary boot code" and a table
+with four entries.  Each of those entries pointed at an arbitrary slice
+of the disk, with one of them was marked "active".  The machine would boot
+by reading the first sector containing the boot code into RAM and then
+jumping to it.  The job of this small piece of boot code was to look at
+the 4 entry table and decide which OS was to be booted by looking
+for the "active" flag.   It would go and load the first sector of that slice
+of the disk into RAM and then and jump to it in turn.  This bit of boot
+code was called the "secondary boot", and could be specific to a given
+operating system.  The primary boot code and 4-entry table is known
+as the Master Boot Record, or MBR, and is very important to the proper
+operation of your PC!  We will discuss the MBR in more detail later.
+
+It was later realized, with the hindsight that IBM is famous for, that disks
+could be bigger than the 32Mb that the early DOS FAT-12 file system could
+handle, so they added a kludge:  They had two MSDOS slices, a "Primary" and
+a "Secondary".  The primary could still only be 32Mb, but the Secondary had
+no size limit.  And the trick was that the secondary had ANOTHER "table entry"
+so that now suddenly up to 5 slices could be available to MS-DOS.  The
+Secondary boot record was later made recursive, thus effectively avoiding
+any fixed limit.  Of course, they were still stuck with a maximum of 26 slices
+given the use of "drive letters" in DOS.  Yes, truly DOS was and is an
+utterly terrible operating system, which of course explains its amazing degree
+of success.  Anyway, this all brings us up to today, which is where FreeBSD
+comes in.
+
+
+1.2  What FreeBSD does
 ----------------------
-FreeBSD has, like any other UNIX, a concept of "partitions".  There is no
-difference between a slice and a partition as such, but we use the two 
-words to distinguish between the two different levels of slicing.
+FreeBSD has, like any other UNIX-like operating system, the concept of
+"partitions."  Partitions are used to implement its own "slicing" abstraction,
+and although there is no real difference between a slice and a partition as
+such, we use the two words to distinguish between these two different levels
+of slicing.
 
 The result is that we have a two-tier structure on the disk:
 
@@ -59,127 +79,172 @@ The result is that we have a two-tier structure on the disk:
                      +-------------------+    \    +----------------+
                      |    Partition C    |     --> | swap-partition |
                      +-------------------+         +----------------+
-                     ...
-
-
-Here is the rule-set that FreeBSD uses:
-
-A:  FreeBSD always has a MBR-slice with type 0xa5.  This means that there
-    should always be a MBR-record, even in the case where FreeBSD occupies
-    the entire disk.
-B:  The FreeBSD-slice contains the FreeBSD-disklabel in the second sector.
-C:  The 'C' partition in the FreeBSD-disklabel corresponds to the entire
-    FreeBSD-slice.
+                     |  ...              |
+
+
+Here are the rules that FreeBSD plays by:
+
+A:  FreeBSD always has an MBR slice with type 0xa5 (each of the 4 slices can
+    also have a unique integer identifier so you can tell your DOS slices
+    from your FreeBSD slices from your Linux slices, etc).  This means that
+    there should always be an MBR record, even in the case where FreeBSD
+    occupies the entire disk.
+B:  The FreeBSD slice contains the FreeBSD disklabel in the second sector
+    (remember, the first sector contains the secondard boot code for FreeBSD,
+     which is what prints that FreeBSD prompt at you when you first boot
+     FreeBSD from a floppy or hard disk).
+C:  The 'C' partition in the FreeBSD disklabel corresponds to the entire
+    FreeBSD slice.
 D:  The 'D' partition corresponds to the entire physical disk.
-E:  Should a disk not have a FreeBSD-slice (because there simply is no 
-    FreeBSD on it anywhere), then the MBR-slices are mapped into partitions
-    'E' to 'H' of a artificially created FreeBSD-disklabel.
+E:  Should a disk not have a FreeBSD slice (because there simply is no 
+    FreeBSD on it anywhere), then the MBR slices are mapped into partitions
+    'E' to 'H' of a artificially created FreeBSD disklabel.  This is useful
+    for getting at DOS-only disks.
 
 Therefore, to get FreeBSD onto your disk, you need to do the following:
 
-  1.  Make a MBR-slice for FreeBSD                                  (FDISK)
-  2.  Partition the diskspace in the MBR-slice into partitions  (DISKLABEL)
+  Step                                                          FreeBSD utility
+  ------------------------------------------------------------  ---------------
+  1.  Make an MBR slice for FreeBSD                             (FDISK)
+  2.  Partition the diskspace in the MBR slice into partitions  (DISKLABEL)
   3.  Assign mount-points to the partitions.                    (DISKLABEL)
 
 
-2.  The main-screen
--------------------
-The main-screen shows you the current status,  It shows you which disks
+
+2.  The sysinstall utility
+--------------------------
+
+The sysinstall utility is the program you first see when you boot
+FreeBSD's install floppy.  It is responsible for partitioning your
+disk, creating an MBR slice for FreeBSD, setting up the disklabel
+within that slice and creating filesystems for each FreeBSD partition
+you create within that slice.  It is composed of a number of screens.
+These are described below.
+
+
+2.1  The main screen
+--------------------
+The main screen shows you the current status,  It shows you which disks
 FreeBSD has found, how big they are and how much of it is assigned to 
-FreeBSD in a FreeBSD-MBR-slice.  It also shows the partitions which have
-had a mountpoint assigned to them.
+FreeBSD in a FreeBSD MBR slice.  It also shows the partitions which have
+had a mountpoint assigned to them (not necessarily FreeBSD partitions; 
+FreeBSD is perfectly capable of mounting DOS disks directly).
 
 (H)elp  -- shows you this file.
 
-(F)disk -- enters the Fdisk editor, where you can change the MBR-record.
-   This is what you want to use to assign some part of the disk to FreeBSD.
+(F)disk -- enters the Fdisk editor, where you can change the MBR record.
+ This is what you want to use to assign some part of the disk to FreeBSD.
 
 (D)isklabel -- enters the Disklabel editor, here you can change how the
-   FreeBSD slice is used.
+ FreeBSD slice is partitioned for FreeBSD.
 
 (Q)uit -- will continue the installation process.
 
 
-3.  FDISK - how to make an MBR-slice
+2.2  FDISK - how to make an MBR slice
 -------------------------------------
-There is some rules to follow everywhere, and the MBR is a potential mine-
-field.  There is no way to really make sure that you have a valid MBR.  It
-is very complicated to write a validation check for it, because there are
-no real rules.
+There are some rules to follow here since altering your MBR is a potential
+minefield.  There is really no way for the sysinstall program to genuinely
+know that you have a valid MBR, so you have to be extra careful in what
+you edit.  Failure to do this properly can and will destroy your other
+operating system entries!
 
-Even if you don't plan to have MSDOS on this disk, make a MSDOS slice
+Even if you don't plan to have MSDOS on a disk, make an MSDOS slice
 using the MSDOS's FDISK.COM program.  The reason for this is that if you
 do it that way, you are 100% sure that FreeBSD will use the same number
-of heads, sectors and cylinders as MSDOS would use.  If you don't plan
-to have MSDOS on the disk, just (D)elete the slice in the FreeBSD's
-(F)disk editor.
+of heads, sectors and cylinders as MSDOS would use.  If you really don't plan
+to have MSDOS on the disk, just (D)elete the slice in the FreeBSD's (F)disk
+editor.
 
-From the main-screen press 'F' to enter the MBR editor.  You have five
+From the main screen press 'F' to enter the MBR editor.  You have five
 commands available:
 
-(H)elp -- Will launch you into this file.
+(H)elp -- Shows you this file.
+
+(D)elete -- Deletes a slice entirely.
 
-(D)elete -- Will delete a slice entirely.
+(E)dit -- Allows you to edit a slice.  It will ask how many megabytes
+  you want to assign to the slice, and will suggest the maximum possible
+  as a default.  It might say zero, even though there is disk space available,
+  in which case you will probably need to delete and recreate the other
+  partitions to get it to see where the free space is.
+  It will then ask you what type to give the slice, for which the default is
+  0xa5 (a FreeBSD slice).  You can enter any other number here too, which can
+  be useful as a placeholder for some other OS you plan to install later.
+  Finally, it will ask you about the "boot flag".  0x80 means "boot from this"
+  slice by default, and anything else means "don't".
 
-(E)dit -- Will allow you to edit a slice.  It will ask how many megabytes
-   you want to assign to this slice, and will suggest the maximum possible
-   as default.  It might say zero, even though there is disk-space available,
-   then you need to delete and recreate the other partitions to get the 
-   puzzle solved.  It will then ask you what type to give the slice, and
-   the default here is 0xa5, which is a FreeBSD slice.  You can enter any
-   other number here too, which can be useful as a placeholder.  Finally
-   it will ask you about the "boot-flag", 0x80 means "boot from this" and
-   anything else means "don't".
-   If you specified a FreeBSD slice, any existing slices witht the 0xa5 
-   type will be reset to 0x00 "unused".  FreeBSD only supports one slice
-   per disk for FreeBSD.
+  If you specified a FreeBSD slice, any existing slices with the 0xa5 
+  type will be reset to 0x00 "unused".  FreeBSD only supports one slice
+  per disk for FreeBSD.
 
 (R)eread -- This is your "undo" function.  It will read the data of the
-   disk again.
+  disk again, disposing of any changes you may have made.
 
 (W)rite -- When you are satisfied with the data, this function will write
-   the new MBR to the disk.
+  the new MBR to the disk.
+
+(Q)uit -- Go back to the main screen.
 
-(Q)uit -- Go back to the main-screen.
 
+2.3  Disklabel - How to divide up the FreeBSD slice.
+----------------------------------------------------
 
-4.  Disklabel - How to divide the FreeBSD-slice.
-------------------------------------------------
+The disklabel screen provides the following commands:
 
-(H)elp -- Will launch you into this file.
+(H)elp -- Shows you this file.
 
-(S)ize -- Will resize a partition for you, it will suggest as default the
+(S)ize -- Resizes a partition for you, it will suggest as a default the
    maximum amount of diskspace it can find.  This algorithm isn't too smart
-   so it might say zero, even though there is diskspace available.  If it
+   and may say zero, even though there is diskspace available.  If it
    does, delete and resize the other partitions.
 
 (M)ountpoint -- Here you assign where the filesystem in a partition is to
-   be mounted.  'b' partitions will always be made into "swap" partitions.
+   be mounted.  `b' partitions will always be made into "swap" partitions.
 
-(D)elete -- Will delete a partition.
+(D)elete -- Delete a partition.
 
-(R)eread -- Is a undo function.  It will reread the current disklabel from
+(R)eread -- The undo function.  It will reread the current disklabel from
    the kernel.
 
 (W)rite -- This will write the disklabel to the disk.  You must always write
    before you quit, otherwise your changes will be lost.
 
-(Q)uit -- Exit back to the main-screen.
+(Q)uit -- Exit back to the main screen.
+
+
+2.4.  Hints on partition sizing
+-------------------------------
+
+While it's impossible to say how much space you're going to want to
+make your various partitions without knowing more about your intended
+applicatins, here are some good rules of thumb to follow:
+
+1. Root (/) should be at least 18MB, and probably no more than 50MB unless
+   you have some special reason for making your root partition really
+   large.  Remember that the root filesystem is only supposed to contain
+   vital system files and little else.
+
+2. Swap should be at least 2*memory.  That is to say if you have 8MB of
+   memory, then you probably want 16MB of swap.  Even more swap space
+   certainly doesn't hurt, if you can afford to allocate it, and you should
+   also think ahead a little to any planned memory upgrades you may have
+   in mind since increasing this later can be very painful!
 
+   If you're going to run the X Window System (XFree86), you should also
+   consider having a *minimum* of 16MB of swap, since X tends to really
+   use it up.
 
-5.  Some hints on diskspace needed
-----------------------------------
+3. /usr can take up the rest of your disk, though some people like to create
+   extra partitions for user home directories and the like.  Be sure to make
+   your /usr big enough to contain the system software (about 50MB) and perhaps
+   some of your own, unless you're going to use symbolic links to point things
+   like /usr/local (or /usr/src) somewhere else.
 
-5.1  Swapspace
---------------
-Always assign at least as much diskspace to swap as you have RAM in the 
-machine.  If you expect to run X11 (XFree86) on the machine, twice that
-amount.
 
-5.2  Filesystems
-----------------
+Here are some suggested filesystem names and sizes, just for reference:
 
-Mountpoint	Filesystem-size
+Mountpoint	Filesystem size
 -------------------------------
 /var		10Mb
 /usr		50Mb
@@ -191,4 +256,4 @@ Mountpoint	Filesystem-size
 /usr/X11R6	50Mb	If you load the entire XFree86 binary kit.
 
 
-$Id$
+$Id: DISKSPACE.FAQ,v 1.1 1994/11/05 05:54:21 phk Exp $