[gentoo-user] Re: Install from USB stick; here's how

[Grant Edwards <grant.b.edwards@gmail.com>]

On 2013-09-03, Alan McKinnon <alan.mckinnon@gmail.com> wrote:
> On 03/09/2013 19:05, Grant Edwards wrote:
>> On 2013-01-07, Walter Dnes <waltdnes@waltdnes.org> wrote:
>> 
>>>   For those of you who don't want to do the tap-dance listed at...
>>> http://www.gentoo.org/doc/en/liveusb.xml
>>>
>>> * My netbook's harddrive is normally /dev/sda, except when I boot from a
>>>   USB stick.  The stick will become /dev/sda and the harddrive becomes
>>>   /dev/sdb
>>>
>>> * My desktop's harddrive is also /dev/sda.  I took the linux minimal
>>>   install ISO, ran isohybrid on it, with the command...
>>>
>>> isohybrid install-x86-minimal-20121213.iso
>>>
>>>   If you don't have isohybrid...
>>>
>>> emerge sys-boot/syslinux
>>>
>>> * I then copied it over to a USB stick (/dev/sdb) with the command...
>>>
>>> dd bs=4M if=install-x86-minimal-20121213.iso of=/dev/sdb
>> 
>> I did a 64-bit install from USB flash-drive a few days ago using the
>> older tap-dance, and it worked fine -- except I discovered one of my
>> "must have" apps is 32-bit only and didn't work correctly when run in
>> 32-bit emulation mode (I don't know why).
>> 
>> So I tried Walter's recipe yesterday to do a 32-bit install.
>> 
>> After running the isohybrid command, I compared the resulting image
>> with the original.  They were identical.  I copied the image to a USB
>> flash drive, and it booted just fine.
>> 
>> It seems that the minimal install .iso images are already built for
>> hybrid booting from either CD or a generic block device (e.g. USB
>> mass-storage device).
>> 
>> So what's the deal with http://wiki.gentoo.org/wiki/LiveUSB/HOWTO?
>> 
>> Why isn't it just the steps below?
>> 
>>   1) Copy the minimal install .iso to USB mass storage device.
>> 
>>   2) Boot from USB mass storage device.  
>
> Copying an .iso to a USB stick does not give you a bootable USB
> stick.

It does for recent Gentoo minimial install .iso images.

> It gives you a USB stick with one large file, without bootloader, and
> the BIOS code can't make sense of it.

All my machines seem to.

> USB mass storage devices are not CDs, you can't just dd an ISO9660
> image to a USB stick and expect it to work

But it _does_ work.  I tried it with a couple different minimal
install .iso files and a couple different machines.

-- 
Grant Edwards               grant.b.edwards        Yow! What's the MATTER
                                  at               Sid? ... Is your BEVERAGE
                              gmail.com            unsatisfactory?