Garrett Cooper youshi10 at
Sat Mar 24 05:25:09 UTC 2007

Jerry McAllister wrote:
> That still, unfortunately does not tell me the whole story.  The reason
> is that there are still some places where the word partition is misused
> (used unconsistently with the rest of FreeBSD).   In FreeBSD the primary
> division of the disk is called a slice.    Slices are then subdivided
> in to partitions in FreeBSD parlance.   
> The hierarchy of terminology goes like this:
>  -drive:         ad0 (for IDE family including SATA)  da0 (for SCSI family) 
>                  would designate the first drive.  The second would be
>                  either ad1 or da1.
>  ---slice:       ad0s1..ad0s4 - Up to four slices numbered from 1-4.
>                  MS is typically installed in slice 1 or 2 (depending if
>                  the vendor sticks a diagnostic/recovery slice on first.
>                  Dell likes to do that and I think IBM Lenovo does)
>  -----partition: ad0s1a..ad0s1h.   Up to 8 partitions per slice but
>                  partition c is reserved to identify the whole slice
>                  partition is used for root and traditionally reserved
>                  for that, though it can be used otherwise on a non-boot
>                  disk.   partition b is used for swap and is traditionally
>                  reserved for that.

Hmm I got educated. After doing a bit of research it appears that what I 
once knew as partitions and slices were backwards:

The above link contains as much information as Jerry provided, and 
possibly some extra info. I only briefly touched the article by in seems 
pretty complete.

> So, what you are supposed to be looking for is a slice in which to 
> install FreeBSD.  It may be that you are seeing the word partition where 
> it should say slice or it may be that you are seeing partition correctly
> used, but you are looking in the wrong place.

Yes, and as I discovered FreeBSD slices are MS(/Linux?) partitions :).


> If the MS slice is an NTFS type, then those free utilities can not
> handle it and you will have to go get something.   The one I have
> successfully used is called 'Partitin Magic' and it tends to run
> about $70 give or take, from most retailers, mail order or walkin.
> I got mine at Best Buy.   Partition Magic will also handle the FAT
> and FAT32 type MS Primary Partitions.    

There's also another free utility available on Knoppix I believe that 
resizes partitions. I highly suggest backing up your data before doing 
anything, because although NTFS is marked stable for writing, I question 
whether or not the penguin might run off with your data if something bad 

> In either case, you shrink the MS slice (Primary Partition) enough to 
> make room for what you want.  Then you create a slice (Primary Partition)
> in the newly made free space.   It needs to be a Primary Partition
> and not an Extended Partition.  Partition Magic whines about that and
> warns you that you might not be able to boot MS.   But it will do it
> and it works just fine.    In Partition Magic terminology, create that
> new Primary Partition as an 'unknown' type.   The FreeBSD installer
> will modify the type during install.

Sidenote: If you do use partition magic after installing Unix, don't let 
it "fix" your disk. It'll muck up your bootloading scheme.

> Just a side note:   FreeBSD can read and write FAT and FAT32.  It can
> read, but cannot write NTFS (at the current time).  If you have enough 
> room to spare on the disk, you might want to make two new Primary
> Partitions.  (remember, you can have up to 4).   Make one rather small
> one, maybe a couple of GB or so, right next to the MS NTFS slice and
> and make it a FAT32 type.  Then put FreeBSD in the one after that.  It
> would make the extra one be slice 2 if no vendor slice and 3 if there
> is a vendor diagnostic slice.  FreeBSD would then be in slice 3 if no
> vendor slice or 4 if there is a vendor slice.   What this little 
> extra slice becomes is a space where both MS and FreeBSD can read and
> write and means you can use it to shuffle files back and forth.

Windows can also read (and in some cases) write to Reiserfs, and can 
write to ext2 partitions (after you install some utilities for 
interfacing with the filesystems). Freebsd can read/write with the 
previously mentioned filesystems (albeit with some extra functionality 
built into the kernel). Reiser and ext(n) are both commonly used in the 
linux realm as filesystems of choice. ext(n) doesn't have write based 
journal support, which means that you can lose data if you unproperly 
unmount the filesystems / shut down the machine. Reiser doesn't support 
writing yet either because it's strictly a journaling based filesystem.

> OK. Fourth, to check this out and just see what is on that disk,
> boot up the disc1 CD and when you get the big menu, choose to
> run the fixit.    When you get the prompt for the fixit, you will be
> in a fairly complete, (but still somewhat limited) version of FreeBSD.
> Figure out what your drive name is - probably either ad0 or da0 (run
> dmesg and pick through the output looking for the disk identifier - 
> don't forget you can do scroll-lock and page up in the console)  and
> then run fdisk on the drive with no other parameters,  eg.   fdisk ad0

ad(n) -> EIDE / PATA
da(n) -> SATA / SCSI

where n denotes the disc numbering on the channel in use, i.e. 0 -> 
first disk (primary master in EIDE world, ID 0 in SCSI world, and port 
labeled SATA1 in SATA world).


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