Re: [gentoo-user] Partition of 3TB USB drive not detected

[james <garftd@verizon.net>]

On 07/31/2016 08:37 AM, Jörg Schaible wrote:
> Hi,
>
> for my backups I use a 3TB USB drive (one big ext4 partition) without any
> problems. Just plug in the cable, mount it and perform the backup. The
> partition (sdi1) is detected an mountable without any problems:

this tells you the device is valid and working. good.
>
> However, when I boot a rescue system from a USB stick, the partition on the
> USB is not detected. I already tried latest SystemRescueCD (default and
> alternate kernel), Knoppix and the Gentoo Admin CD. Nothing, the partition
> is not available.

So there could be a multitude of reasons. Did thos systems have a bios 
that support booting from a usb device? Are the bios setting set to 
select the bios device correct?

I recently read somewhere the usb devices only support (2) types of 
image booting, but I cannot find that doc right now. rodsbooks is
an excellent resource for all the issues around booting and device
and various hardware/firmware issues. LikeWhoa has made booting the usb 
for gentoo, commonplace so search out those postings on the gentoo 
forums and in the wiki.


> What's the difference? Why does my kernel find this partition and the other
> one's do not? It's pretty silly to have a backup drive and cannot access it
> in question ;-)

It could be many things. You just have to ferret thru ideas until 
something works for your hardware, and it is a frustrating process.

make sure the image you are trying to boot is on a compatible partition 
and file system that is supported by the boot image.


hth,
James