Benchmarking

Matthew Dillon dillon at apollo.backplane.com
Mon Mar 8 09:59:10 PST 2004


:One thing -- I don't understand why the first step is to totally zero 
:out the hard disk.  Most people would already have a partition (slice) 
:on which they want to install the thing (so they can skip the zeroing 
:and fdisk step), or would have another OS installed and would want 
:to repartition retaining that OS (so the README could point them at
:third-party software like Partition Magic).  And since (I believe) 
:that's "most people", it's not true that "DragonFly is typically 
:installed onto the first slice (ad0s1)."  Very likely they want to 
:skip the boot0cfg step too, if they have lilo/grub/WinNT bootloader
:working.

    Many BIOS's are sensitive to 'cruft' in the boot area.  Cruft often
    occurs when you've installed different boot blocks over time, because
    of the read-modify-write nature of boot block installation (boot block
    installers generally try to keep the fdisk area intact).  Also, boot1
    and boot2 (which get installed in the slice) have changed their size and
    location over time.  Especially boot2, and for some unknown reason some
    BIOS's are sensitive to this, possibly because some BIOSes try to probe
    the slices as logical fdisk sub-partitions.  Also, older boot blocks
    contain bad geometries which can cause BIOSes to crash.

    What this all means is that diagnosing boot block installation problems
    is difficult at best if one does not start with a clean slate. 

    If someone wants to submit a patch for the README to clarify the issue,
    please do!

					-Matt
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>





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