36.4GB drive formats out to 32.8GB? what am I missing please

[Chris]

Grant wrote:
> On Sun, 5 Jun 2005 11:44:19 -0700
> "D. Goss" <lists at dylangoss.com> wrote:
> 
> 
>>I am adding some drives to an IBM xSeries 345.  I recently picked up  
>>(via eBay) an IBM packaged Seagate drive, all with the proper IBM  
>>part numbers as:
>>
>>U320 15k
>>36.4GB formatted capacity
>>(IBM part 06P5776 / 06P5778, with Seagate drive ST336753LC)
>>
>>Looking up both the IBM part numbers and the Seagate part numbers via  
>>Google, I consistantly get that the drive's formatted capacity is  
>>36.4GB.
>>
>>When partitioned either in "safe" or "dd" mode (via sysinstall) and  
>>set to use the entire disk as one slice, once the drive is mounted I  
>>show:
>>
>># df -m
>>/dev/da1s1      33617    0 30928     0%    /misc
>>
>># df -h
>>/dev/da1s1      33G    4.0K     30G     0%    /misc
>>
>>I'm seeing approx. 30,600MB (32.8GB?) free -
>>
>>Is this correct?
>>
>>Thanks!
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> 
> 
> Hey,
> 
> I think the problem that you are seeing is due to freebsd reserving some space for the root user.
> 
> Somewhere in the handbook is says when you format a drive there will be around 10% of the drive reserved for root.
> 
> I think you can change that number but you will have to look in the handbook for that.
> 
> Hope this helps
>>From Grant.

This is not entirely correct - Let's think back... Even tho a drive is
specked for 36 gig, rarely is it ever the full 36 gig.

Diff companys use diff figures as to what a meg is. For example, IBM
(iirc) uses 1000 k for a meg while others use 1.4 etc.

Drives when formatted are never as large as they claim to be.

-- 
Best regards,
Chris

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