amd64/155023: Bad propose size in disklabel during install

[Fabrice]

>Number:         155023
>Category:       amd64
>Synopsis:       Bad propose size in disklabel during install
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-amd64
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Feb 25 10:20:09 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Fabrice
>Release:        8.2
>Organization:
Orange Business Service
>Environment:
NA : problem during install
>Description:
I'm try to install FreeBSD 8.2 amd64 on a ESXi 4.1. I create a virtualdisk of 20Go and so I boot on the 8.2 iso 

During install, in disklabel,the size af the disk before any action :
Disk: da0 Partion name: da0s1 Free: 41929587 blocks (20473MB)

I choose first "A auto defaults" and so disklabel create :
da0s1a    /         1024MB UFS2   Y
da0s1b    swap      4061MB swap
da0s1d    /var      6126MB UFS2+S Y
da0s1e    /tmp      1024MB UFS2+S Y
da0s1f    /usr      8237MB UFS2+S Y

To be able to compile the world, I want change the size of / and /tmp.

So I delete /tmp / and /usr
Disklabel say :
Disk: da0 Partion name: da0s1 Free: 21065651 blocks (10285MB)
So I create manualy / with size = 2G and /tm with size = 2G

At this time I can read :
Disk: da0 Partion name: da0s1 Free: 12677043 blocks (6189MB)

da0s1b    swap      4061MB swap
da0s1d    /var      6126MB UFS2+S Y
da0s1a    /         2048MB UFS2   Y
da0s1e    /tmp      2048MB UFS2+S Y

I do "Create" and disklabel show in the box "value required" 12677043. I select OK, FS mount point /usr and the following error message appeared :

"Unable to create the partition. Too big ?"

To create the /usr  partition, the bigger value I can use for /usr is 5100M and so I can see :

Disk: da0 Partion name: da0s1 Free: 2232243 blocks (1089MB)

da0s1b    swap      4061MB swap
da0s1d    /var      6126MB UFS2+S Y
da0s1a    /         2048MB UFS2   Y
da0s1e    /tmp      2048MB UFS2+S Y
da0s1f    /usr      5100MB UFS2+S Y


>How-To-Repeat:

>Fix:
No really fix, all space on partition is not use 

>Release-Note:
>Audit-Trail:
>Unformatted: