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diff --git a/share/FAQ/diskspace.FAQ b/share/FAQ/diskspace.FAQ deleted file mode 100644 index 31346df050b3..000000000000 --- a/share/FAQ/diskspace.FAQ +++ /dev/null @@ -1,267 +0,0 @@ - How to assign disk space to FreeBSD. - -$Id$ - -1.0 Getting started. ---------------------- - -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 (or may not) 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 manageable 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 "slices". What it had was a way to install -Xenix and MS-DOS on the same disk (Remember when Microsoft were in the UNIX -business?). - -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. They also reserved -only 10 bits for cylinder addressing, limiting DOS to being able to address -a maximum of 1024 cylinders (and cause of the dreaded "cylinder translation" -kludges, the misconfiguration of which many users have seen as the notorious -"Missing Operating System" message). 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-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: - -+-----------+ -| MBR-table | -+-----------+ +---------+ -| Slice 1 | -----> | MSDOS | -+-----------+ +---------+ -| Slice 2 | -+-----------+ +-------------------+ -| Slice 3 | -----> | FreeBSD-disklabel | -+-----------+ +-------------------+ +-----------------+ -| Slice 4 | | Partition A | -----> | Root-filesystem | -+-----------+ +-------------------+ +-----------------+ - | Partition B | --- - +-------------------+ \ +----------------+ - | Partition C | --> | swap-partition | - +-------------------+ +----------------+ - | ... | - - -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 secondary 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 an 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: - - Step FreeBSD utility - ------------------------------------------------------------ --------------- - 1. Make an MBR slice for FreeBSD (FDISK) - 2. Partition the diskspace in the MBR slice into partitions (DISKLABEL) - 3. Assign mountpoints to the partitions. (DISKLABEL) - - - -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 (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. - -(D)isklabel -- enters the Disklabel editor, here you can change how the - FreeBSD slice is partitioned for FreeBSD. - -(P)rocede -- will continue the installation process. - -(Q)uit -- Go back to the entry screen. - - -2.2 FDISK - how to make an MBR slice -------------------------------------- -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 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 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 -commands available: - -(H)elp -- Shows you this file. - -(D)elete -- Deletes 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". - - 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, 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. - -(Q)uit -- Go back to the main screen. - - -2.3 Disklabel - How to divide up the FreeBSD slice. ----------------------------------------------------- - -The disklabel screen provides the following commands: - -(H)elp -- Shows you this file. - -(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 - and may say zero, even though there is diskspace available. If it - does, delete and resize the other partitions. - -(A)ssign -- Here you assign where the filesystem in a partition is to - be mounted. `b' partitions will always be made into "swap" partitions. - -(D)elete -- Delete a partition. - -(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. - - -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. - -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. - - -Here are some suggested filesystem names and sizes, just for reference: - -Mountpoint Filesystem size -------------------------------- -/var 10Mb -/usr 50Mb -/ 16Mb - -/usr/src 120Mb If you want to have the sources online -/usr/obj 100Mb If you want to compile all of them at one time - -/usr/X11R6 50Mb If you load the entire XFree86 binary kit. - - -$Id: diskspace.FAQ,v 1.1 1995/01/03 15:48:36 gclarkii Exp $ |