A USB drive as (1) 160 GB partition sole purpose data

[Amedee Van Gasse (ubuntu)]

Amedee Van Gasse (ubuntu) schreef:
> (fixed quoting order)
> Juan De Mola schreef:
>> On 4/25/09, allen meyers <texas.chef94 at gmail.com> wrote:
>>> I will state what I am doing, not attesting to it being right and await
>>> your critique.
>>> 1.I can plug it in, go places and it shows on left tree 160GB. To the
>>> right is a data folder and right of that folder Lost+found
>>>
>>> 2. I can right click on a given file to move to said partition, choose
>>> send, the, removable disk & shares, send to 160GB media
>>>
>>> 3. When I right click on 160GB icon + properties I see the file pie as
>>> if I was in windows C and it shows the presence of what I sent, but not
>>> titled.
>>>
>>> 4. This begs the question of an option to move data to partition titled
>>> so that it can be retrieved edited or used please advise
>>>
>>> Finally because I have experienced 2 error 15's I am reluctant to shut
>>> down until someone advises me as to the following
>>> (a) is it safe to unmount leave plugged in and shutdown with no danger
>>> of an error 15 at reboot.
>>> (b) is a safer course unmount, unplug, shut down
>>> (c) Finally at reboot assuming used option (b) is it plug in, boot or
>>> boot, plug in.
>>>
>>> Please advise
>>>
>> And what fs has the partition?
> 
> Actually that does not matter at all.
> 
> I have the same problem: if I leave an usb disk plugged in at reboot, I
> also get a GRUB error 15.
> Tested and verified with fat32 and ext3.
> 
> I have only two workarounds:
> 1. never reboot
> 2. when I reboot, first unplug all usb devices, reboot, and only after
> grub and the kernel are loaded, plug the usb devices back in.
> 

For the record: this is an unsolvable bug.

The problem is that grub guesses the BIOS disk order incorrectly. When
you boot without the usb disk, your first hard disk becomes sda=hd0. But
with the usb disk plugged in, /that/ becomes sda=hd0. And of course the
usb disk doesn't have any grub files.

You can try editing /boot/grub/device.map, and that will solve the
problem when your usb disk is plugged it, but then you have created a
new problem: now you will get grub error 15 when your usb disk is _not_
plugged in.

Don't try to fix this by messing around in the boot order of your BIOS:
it will only make it more complicated - that is my experience.

See also this bug report:
https://bugs.launchpad.net/ubuntu/+source/grub/+bug/8497


So, to summarize, a clean reboot goes like this:
1. unmount all usb disks
2. unplug all usb disks
3. shutdown or reboot linux
4. start the computer (automatic if you reboot)
5. choose your os+kernel in the grub menu and press enter
6. plug in usb disks
7. mount usb disks

I advise against automounting usb disks in /etc/fstab.
You can add a line there, but make the disk user-mountable (man fstab
for more info).
Of course no line is needed in /etc/fstab if you let Ubuntu automount
the disk when it is plugged in.


I hope this helps.
DISCLAIMER: All of this is based on my personal experiences on my
system. Your mileage may vary. Please read the relevant man pages before
changing your configuration, and ask advice if you aren't sure. If you
break your system, you get to keep both pieces, just don't blame me!

Kind regards,

-- 
Amedee


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 835 bytes
Desc: OpenPGP digital signature
URL: <https://lists.ubuntu.com/archives/ubuntu-users/attachments/20090426/912d2695/attachment.sig>