Wipe grub ....?

Forum: USB booting
Topic: Wipe grub ....?
started by: Mr Green

Posted by Mr Green on Sep. 29 2005,10:58

I am having problems with grub on my pendrive....

Installed DSL (USB-HDD) no problem, under qemu works great ..

Now with bios set to boot USB-HDD (first device)

I get Grub error 15

Wondering ifgrub on my main drive (hda) would affect it ...?

Wiped pendrive & tried to reinstall grub but no go...

My old machine had no problems booting usb, this is first time I have tried on machine just wondering if I need to enable usb-keyboard... if so why?

/me keeps looking for the answer .....

MrGreen

Posted by doobit on Sep. 29 2005,15:57

Hmmm. You are right that grub should be on the first boot drive, unless your BIOS is a little screwy and looks first for the MBR on the other drive anyway.

Posted by Mr Green on Sep. 29 2005,18:36

I thought pendrive was wiped clean, that meant it could not boot (unless!!!!)

Could be my grub install on (hda) is out ??

emmm back to lilo to test lol

Posted by doobit on Sep. 29 2005,18:53

The first line in GRUB should be
default=0
that defines what OS grub boots first (the first one in the list)

What does your menu.lst file for GRUB look like?

You can define boot drives with the GRUB utility like this:

# grub
grub> root (hd0,1)
grub> setup (hd0)
grub> quit

Posted by Mr Green on Sep. 30 2005,07:01

Hi,

I have grub installed on my main system (hda)

Wiped pendrive because of grub error....

Now with USB-HDD set to boot first system locks at grub error 15

If I remove pendrive restart machine system boots fine ...

Now I'm thinking that something on pendrive is preventing system from booting ....

output from cfdisk

Code Sample

cfdisk 2.12q

Disk Drive: /dev/sda
Size: 261881856 bytes, 261 MB
Heads: 9 Sectors per Track: 56 Cylinders: 1014

Name Flags Part Type FS Type [Label] Size (MB)
------------------------------------------------------------------------------
sda1 Boot Primary Linux ext3 [Pendrive] 261.67

I'm thinking that maybe setting sda1 as bootable is a bad idea ...

I need a way to wipe all pendrove clean any ideas??

Posted by doobit on Sep. 30 2005,12:31

Did it boot OK from the pendrive before? If not, then maybe it's a pendrive geometry problem. Anyway, to format the pendrive, you would boot normally to the HDD, open cfdisk, highlight the partition that's listed with your up/down arrow keys, and then select delete with the right/left arrow keys. Then make a new partition, and format. The instructions for that are in the DSL Wiki, and there's an important part there about setting your pendrive's geometry. Also, it's not recommended using extf3 to format the pendrive because it uses a little extra space to write the file system info, and it can get corrupt, and no Windows machine can read it if you should need that. I think the Wiki recommends FAT32.

PS. here's another good link on cfdisk: < http://www.linux.com/howtos/IBM7248-HOWTO/cfdisk.shtml >

Posted by Mr Green on Sep. 30 2005,12:55

Hi,

ext3 ahh ok I can change that ...

It did boot before on my old machine .... np

I'll try to reformat drive again ...

When dsl installs to pendrive does it do all that anyway?

Just not sure if my (hda) grub is failing or.. grub is still present on pendrive but cannot find /boot/grub ....

I should not need grub anyway on pendrive as dsl uses syslinux ( I think!!) ,

The reason I used grub was that I did not have to change drive heads (geometry) etc..

When working gives you a nice menu (you know that!!!) ..

Anyway I'll keep at it, I do not give up that easy

Thanks for your help

MrG

Posted by doobit on Sep. 30 2005,14:58

Good. Don't give up because we will all learn something from this. I'm at a loss at this point because I'm only a little past noobee stage. I'll tell you what I know. There is a syslinux install, available, but I think you still need a bootloader when you install to the pendrive. A bootloader, like grub, can reside on the MBR of the main hard drive and point to the pendrive for the OS, or it can reside on the pendrive if your computer's BIOS is able to see it as a boot device. It is possible that something in the boot directory of the pendrive is corrupt, so reformatting and reinstalling will fix it. You are right that grub can install past cylinder 1024. However, the limitation still seems to exist with pendrives. I'm not sure why, but anyway, here's the link in the Wiki: < http://www.damnsmalllinux.org/wiki....rive??? >

Posted by doobit on Sep. 30 2005,15:02

I found another interesting link that my help you:

< http://fuzzymunchkin.dyndns.org/tdot/usbkeyfob/ >

Posted by Mr Green on Sep. 30 2005,15:20

Cool thanks very much...

Posted by iLovePinguins on Oct. 01 2005,23:30

i have made a similar mistake
don't install as usb-hdd BIOS can't handle the ext3 or any other than FAT
it will not work on usb-sticks

don't know why but i have tried it with different systems (dsl,insert,puppy)

only the usb-pendrive installations seems to work well

Posted by Mr Green on Oct. 02 2005,10:45

Hi,

I have a feeling this is why there are so many posts on installing to usb..

Its very hit & miss .....

I found using grub on stick worked ... even split drive to two partitions ... one for /boot other for /dsl etc.. that seemed to work ...

My new system does not want to have any of it ... lol

Set bios for USB-HDD & it finds stick ...

What gets me if I run qemu ... dsl boots fine ...(qemu /dev/sda1)

I thought usb-hdd dsl intall format was fat ? .... guess thats do it works with windows ...

does it make that much difference which fs you use?

provided you are not reading & writing all the time

Confused you will be lol

MrG

Posted by Mr Green on Oct. 06 2005,08:51

Ok...

I have switched from grub (hda) to lilo ... & pendrive still complains grub error 15 ...

Sooo I guess grub is still present on drive

two options

1) Wipe it from pendrive

2) add /boot/grub/menu.lst see I can get it working again

If anyoner knows how to nuke pendrive please let me know ;-)

MrG

Posted by doobit on Oct. 06 2005,13:05

I nuked mine by accident, so I know. sudo su, mount sda1, load cfdisk, delete the partion on sda1. Make sure you don't delete the partion on hda1 or sdb1 or anything else, like I did. :angry:

Posted by Mr Green on Oct. 06 2005,13:28

Hi,

Would grub be on sda ?...I need to wipe that ....

mbr ... whatever lol

*shivers* My nightmare wipin' me hard drive ...