Which disk is which

John summer at computerdatasafe.com.au
Mon Aug 30 21:55:54 UTC 2004


Kevin D. Kinsey, DaleCo, S.P. wrote:
> Hi, John ...
> 
> As you cc'ed doc@, I'm sending your original mail to them
> also, so they'll have some background.  Comments inline.
> 
> John Summerfield wrote:
> 
>> I've booted a 5.2.1 miniinstall CD and got to the point where I choose 
>> which disk to install onto.
>>
>> My choices are
>> ad0
>> da0
>>
>> Great. How do I know which disk is which? _I_ could work it out if the 
>> panel displayed information such as
>> Brand
>> Capacity
>>
>>  
>>
> 
> Read the *text* in the handbook.  As an example, the following
> appears on the page that you linked in your recent crosspost to doc@:
> 
>    "Consider what would happen if you had two IDE hard disks, one
>    as the master on the first IDE controller, and one as the master
>    on the second IDE controller. If FreeBSD numbered these as it
>    found them, as ad0 and ad1 then everything would work.
> 
>    But if you then added a third disk, as the slave device on the first
>    IDE controller, it would now be ad1, and the previous ad1 would " ....
> 
> <>This goes on for another 3-4 paragraphs; it is a discussion of why 
> FreeBSD
> has basically "hardcoded" disk drive names/numbers into the kernel, (e.g.,
> why IDE primary master will always be ad0, why secondary slave will always
> be ad3, etc).
> Then again, just above figure 2-16 (which is the same as figure 2-20
> but without an "X" in the checkbox):
> 
> Figure 2-16 
> <http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/install-steps.html#SYSINSTALL-FDISK-DRIVE1> 
> shows an example from a system with two IDE disks.
> They have been called ad0 and ad2.
> 
> 
> Based on reading these sections/statements of the manual, it would seem
> somewhat obvious that ad0 is the primary master IDE hard disk.  It is
> hard, then, at least for me, to see this as a fault of the documentation.
> 


The drawback to this is that you're writing from the POV of someone who 
knows all this.

I'm not, I don't.

I have booted some other installers on this setup and find they do 
provide more information than the bare OS-dependant name.

Ideally, on my system, the installer would say:
AD0 Internal IDE drive, primary master, WD102AA 10.2 Gb
DA0 External USB drive, Cypress ATMR04-0 40 Gb

so most, even modestly, technical people could instantly recognise which 
disk is which.



More information about the freebsd-doc mailing list