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

[Alan McKinnon]

On 03/09/2013 23:19, Grant Edwards wrote:
> On 2013-09-03, Alan McKinnon <alan.mckinnon@×××××.com> wrote:
>> On 03/09/2013 19:05, Grant Edwards wrote:
>>> On 2013-01-07, Walter Dnes <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.

Now I'm confused, let's clarify. Which of these meanings of copy are you
using:

cp my_big.iso /where/i/mounted/the/stick

dd if=my_big.iso of=/dev/sdb


If it's the first, then you have just discovered serious $COMPUTER_MAGIC
unbeknownst to me thus far :-)


>
>> 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.
>


-- 
Alan McKinnon
alan.mckinnon@×××××.com