Subject: Re: install/31274: can't install with single large partition easily, sysinst menu is inconsistent
To: None <install-manager@netbsd.org, gnats-admin@netbsd.org,>
From: None <pcah8322@artax.karlin.mff.cuni.cz>
List: netbsd-bugs
Date: 10/23/2005 08:07:02
The following reply was made to PR install/31274; it has been noted by GNATS.

From: pcah8322@artax.karlin.mff.cuni.cz
To: gnats-bugs@NetBSD.org
Cc: david@l8s.co.uk
Subject: Re: install/31274: can't install with single large partition easily, sysinst menu is inconsistent
Date: Sat, 22 Oct 2005 22:36:51 +0200

 On Sat, Sep 10, 2005 at 09:36:01AM +0000, David Laight wrote:
 >  > >Description:
 >  > the "partition sizes" menu says: "The default is
 >  > to allocate all the space to the root file system ..."
 >  > (src/distrib/utils/sysinst/msg.mi.en)
 >  > 
 >  > .. the partiton layout with a small / and a large /usr filesystems.
 >  
 >  This will happen if sysinst believes that a / filesystem covering the
 >  whole disk could leave the kernel in an area of the disk that is
 >  inaccessible to the BIOS.  Under these conditions the partition layout
 >  code defaults to a small / and a large /usr.
 >  
 >  This will happen on old systems where the BIOS doesn't support LBA reads, so
 >  the / partition would include sectors that cannot be read using CHS reads.
 >  (note: the default sized SWAP is allowed to be above the CHS boundary).
 
 Thanks for your reply.
 
 I'm almost sure that the BIOS can access the whole 18 GB disk, as Windows
 NT (2000) were installed in a single large FAT32 partition, so their
 bootloader had to be able to access the whole disk (unless they do some
 dirty trick like putting the kernel and all LKMs in the beginning of the
 filesystem, which I strongly doubt).
 
 The machine is Compaq Evo N600c laptop with 1 GHz Pentium III CPU and I
 think it's "new enough".
 
 But the BIOS is probably a bit strange. fdisk says:
 
 Disk: /dev/rwd0d                                                                
 NetBSD disklabel disk geometry:                                                 
 cylinders: 38760, heads: 16, sectors/track: 63 (1008 sectors/cylinder)          
 total sectors: 39070080                                                         
                                                                                 
 BIOS disk geometry:                                                             
 cylinders: 1022, heads: 240, sectors/track: 63 (15120 sectors/cylinder)         
 total sectors: 39070080                                                         
                                                                                 
 Partition table:                                                                
 0: Primary DOS with 32 bit FAT (sysid 11)                                       
     bootmenu: NT                                                                
     start 63, size 11067777 (5404 MB, Cyls 0-732)                               
 1: NetBSD (sysid 169)                                                           
     bootmenu: NetBSD                                                            
     start 11067840, size 16390080 (8003 MB, Cyls 732-1816), Active              
 2: <UNUSED>                                                                     
 3: <UNUSED>                                                                     
 Bootselector enabled, timeout 10 seconds.                                       
 
 the "heads" value looks nonstandard and the BIOS already confused GNU
 Parted, which made NT unbootable by setting the geometry values in their
 boot sector to different values when shrinking the partition.
 
 Also, why did sysinst offer to create circa 0.5 GB root? The NetBSD
 partition starts at ~ 5 GB, and 5.5 GB is not near any BIOS or IDE magic
 limit IIRC.
 
 Bye	Pavel