nstalling GRUB on a disk that is going to be actually installed on a different comput

thefool · 10-08-2010, 11:18 AM

Hello,

I hope I'm wording this issue clearly.

I'd like to plug a disk (IDE or SATA) into an adapter that lets me plug it into my workstation via USB. (E.g. http://www.newegg.com/Product/Produc...82E16817153071)

It will show up as /dev/sdX where X is some arbitrary letter depending on what other disks the system happens to have.

I'd like to have a script then partition, format and copy files onto it. Then we need to install GRUB on it.

Then I will remove the disk and install it permanently into a different computer, here it will either be /dev/hda (if IDE) or /dev/sda (if SATA).

However, it seems that in general when you install GRUB on a disk, it assumes it is going to be the same disk that boots??

I am first trying an IDE disk so it will be /dev/hda.

I get a "GRUB Hard Disk Error" when booting it as /dev/hda rather than whetever it was on the USB adapter. I used this to install grub:

grub-install --root-directory /mnt/removable/ /dev/sdX

Where X was the appropriate letter based on the USB adapter. Then I fixed /mnt/removable/boot/grub/device.map to use /dev/hda../dev/hdc instead of sda..sdc.

I haven't found much about this specific scenario I have so far on the web.

I am guessing that stage1 is either attempting to find files based on what the original workstations primary disk geometry was, or it's assuming that the disk is the same location as it was when it was a "removable" one (i.e. /dev/sdX or (hd5) or whatever, when it should just be looking at (hd0).

The goal is to do this kind of installation easily and quickly, and not have to do it individually on each final computer via install CDROM or whatever, or reboot the workstation each time in order to attach the disk as the same location there, etc. (This is a manufacturing setting).

Thanks for any ideas you have!

Reed

malekmustaq · 10-08-2010, 11:42 AM

Quote:

It will show up as /dev/sdX where X is some arbitrary letter depending on what other disks the system happens to have.

No, it doesn't matter at this instance because Grub is using different labels on partitions: that is, '(hd0,0)' for the first drive first partition. Check again your configuration.

Quote:

However it is most advisable to install grub on the computer that is booting it.

I get a "GRUB Hard Disk Error" when booting it as /dev/hda rather than whetever it was on the USB adapter. I used this to install grub:

grub-install --root-directory /mnt/removable/ /dev/sdX

Do not use 'grub-install' as it will merely guess the drive maps. Use the basic steps of safe commands:

Code:

grub> find /boot/grub/stage1
grub> root (hd0,x)
grub> setup (hd0,x)
grub> quit

Try if this will work when the disk is moved to another machine.

Hope it helps.

thefool · 10-08-2010, 12:52 PM

Thanks! Won't (hd0,x) install it on partion x of my workstation's hard disk rather than the MBR of my desired disk (the removable one on the USB thing)?

Will it also work if I use, say (hd2) there? (If (hd2) is my removable disk)?

What side effect does "find" have, or is it just to determine what (hdN) identifier to use? I do want to automate this process, but I think I can convert the /dev/sdX name I get from HAL when the disk is inserted to a likely grub (hdN)...

yancek · 10-08-2010, 01:39 PM

root (hd0,0) This will install Grub files to the first partition of the first disk, that is if you are using Grub Legacy and not Grub2.

Quote:

Will it also work if I use, say (hd2) there? (If (hd2) is my removable disk)

If you do: root (hd2,0) it will install Grub files to the first partition of the third disk if you are using Grub Legacy.

setup (hd2) This will install Grub stage1 file to the mbr of the third disk.

The find command just tells you where whatever files you are looking for are, what disk and partition.

Grub numbers both partitions and drives beginning with zero.
Grub2 numbers drives from zero and partitions from one.
You didn't indicate which distribution you are using so...?

thefool · 10-12-2010, 04:21 PM

Yeah, it's grub 1 (Debian 5)

Quote:

Originally Posted by yancek

root (hd0,0) This will install Grub files to the first partition of the first disk, that is if you are using Grub Legacy and not Grub2.

If you do: root (hd2,0) it will install Grub files to the first partition of the third disk if you are using Grub Legacy.

setup (hd2) This will install Grub stage1 file to the mbr of the third disk.

The find command just tells you where whatever files you are looking for are, what disk and partition.

Grub numbers both partitions and drives beginning with zero.
Grub2 numbers drives from zero and partitions from one.
You didn't indicate which distribution you are using so...?

syg00 · 10-12-2010, 08:03 PM

All sorts of potential problems with this. Grub (classic) stage1 uses a bitmap to indicate which *BIOS* drive it needs to go talk to for post-stage1. That's effectively what you pass it in the "root (hdx,y)" directive.
The BIOS order may not (often isn't) the same as the order the udev rules and initscripts generate. So getting the two to agree from a terminal invocation is damn near impossible.

Ubuntu used to have a patched grub that would accept UUID - did Debian ever accept that ?.