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Fw: Grub cannot see my new hard drive

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The 4 TB hard drive uses a GPT type partition table, not an MBR type table, which is why the computer can't see it. It can't make sense of GPT tables. It is a Toshiba Satellite laptop. Satellite P105-S6187, model number PSPAAU-01L00S. I just ordered new memory for it yesterday. At the moment one memory card is sitting on top of it with the cover removed. I'll be putting it back together in a moment. It was factory preloaded with Windows Vistsa.

name=Matthew%20Campbell&email=trenix25%40pm.me

-------- Original Message --------
On Jul 1, 2020, 7:50 PM, David Wright wrote:

> On Wed 17 Jun 2020 at 05:14:22 (+0000), Matthew Campbell wrote:
>>
>> I booted from a USB 2.0 flash drive into Grub2. Then I asked Grub for a command prompt. Then I issued the following three commands:
>>
>> grub> linux (hd2,msdos1)/vmlinuz root=/dev/sdb1 ro
>> grub> initrd (hd2,msdos1)/initrd.img
>> grub> boot
>>
>> /dev/sda is the internal hard drive in the laptop computer.
>> /dev/sdb is the new 4 TB Toshiba External USB 3.0 hard drive.
>>
>> /dev/sdc and /dev/sdd are currently USB 2.0 flash drives with an ext4 file system on the first and only partition. Both use a DOS MBR partition table that sets the first partition as active/bootable.
>>
>> The hard drive, /dev/sdb, always responds faster than the USB flash drives so it is always /dev/sdb.
>>
>> Now Debian Linux is running on my new hard drive using /dev/sdb1 as the root partition. I need to set up a separate USB flash drive to do all of this by default so I don't have to do all of this work every time the computer boots up. I also need to install Grub2 on the backup USB flash drive so I can use it to boot my system if something goes wrong and the first USB flash drive that I just used gets screwed up as well.
>
> Perhaps it would be simpler to use a more generic approach.
> You could try installing the package grub-rescue-pc, which
> contains within /usr/lib/grub-rescue/:
>
> -rw-r--r-- 1 root root 5021696 Jun 25 2019 grub-rescue-cdrom.iso
> -rw-r--r-- 1 root root 1255424 Jun 25 2019 grub-rescue-floppy.img
> lrwxrwxrwx 1 root root 21 Jun 25 2019 grub-rescue-usb.img -> grub-rescue-cdrom.iso
>
> (The exact sizes may differ according to amd64/i386 architecture.)
> I copy the ISO file onto any old USB stick that's past its prime.
>
> If that stick boots successfully, you should type:
>
> c for a grub prompt.
> ls to list the drives and partitions that grub can see.
> ESC to exit from the prompt.
> e to edit grub.cfg.
> Change set root=(hd0,msdos1)
> to the appropriate (drive,partition) from the ls output, eg (hd1,gpt4).
> Change root=/dev/sda1
> to the appropriate partition, eg sda4.
> F10 to boot.
> Grub uses the links in your root filesystem to find the appropriate
> vmlinuz and initrd.img. (You might need hd2 and sdb1 for the first
> partition on the second disk.)
>
> Your system should now be running from the hard drive specified.
>
> As you want to streamline this, it makes sense to change those two
> lines on the stick, as appropriate. I tried this out by making a
> local copy of the original grub-rescue-cdrom.iso and editing it with
> emacs. I searched for the string "For boot" to get to the right place,
> and edited as above. gpt4 is shorter than msdos1, so I added a couple
> of spaces after the ). This makes it easier to compare the original
> and the copy by typing
> $ vbindiff your-copy.iso /usr/lib/grub-rescue/grub-rescue-cdrom.iso
> and pressing Enter. The differences will show up in red.
>
> (If you don't have vbindiff, just install the package vbindiff.)
>
> Copy the modified ISO onto the stick, boot it, and press e as above.
> If the menu looks correct, press F10 to boot. Next time you boot
> from the stick, just pressing Return will be enough.
>
> When the USB stick gets ropy, just copy your ISO to another one.
>
> I didn't bother to investigate why emacs added a harmless linefeed
> to the end of the edited ISO.
>
> I'm surprised that you appear to have an MBR partition table on
> the 4TB drive (hd2,msdos1). Is that right or have I misunderstood
> something?
>
> Cheers,
> David.

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Re: Grub cannot see my new hard drive Matthew Campbell <trenix25@pm.me> - 2020-06-17 07:20 +0200
  Re: Grub cannot see my new hard drive deloptes <deloptes@gmail.com> - 2020-06-17 08:50 +0200
    Re: Fw: Grub cannot see my new hard drive deloptes <deloptes@gmail.com> - 2020-06-18 07:00 +0200
  Re: Grub cannot see my new hard drive David Wright <deblis@lionunicorn.co.uk> - 2020-07-02 05:00 +0200
    Fw: Grub cannot see my new hard drive Matthew Campbell <trenix25@pm.me> - 2020-07-02 10:20 +0200
      Re: Fw: Grub cannot see my new hard drive "Thomas Schmitt" <scdbackup@gmx.net> - 2020-07-02 11:20 +0200
      Re: Fw: Grub cannot see my new hard drive David Christensen <dpchrist@holgerdanske.com> - 2020-07-02 21:00 +0200
        Fw: Fw: Grub cannot see my new hard drive Matthew Campbell <trenix25@pm.me> - 2020-07-02 23:20 +0200
      Re: Fw: Grub cannot see my new hard drive David Wright <deblis@lionunicorn.co.uk> - 2020-07-02 22:10 +0200
        Fw: Fw: Grub cannot see my new hard drive Matthew Campbell <trenix25@pm.me> - 2020-07-02 23:20 +0200
          Re: Fw: Fw: Grub cannot see my new hard drive David Wright <deblis@lionunicorn.co.uk> - 2020-07-03 16:40 +0200
            Fw: Fw: Fw: Grub cannot see my new hard drive Matthew Campbell <trenix25@pm.me> - 2020-07-03 19:30 +0200
              Re: Fw: Fw: Fw: Grub cannot see my new hard drive deloptes <deloptes@gmail.com> - 2020-07-03 21:10 +0200
                Re: Grub cannot see my new hard drive David Wright <deblis@lionunicorn.co.uk> - 2020-07-04 04:00 +0200
                Re: Grub cannot see my new hard drive deloptes <deloptes@gmail.com> - 2020-07-04 08:00 +0200
                Re: Grub cannot see my new hard drive "Thomas Schmitt" <scdbackup@gmx.net> - 2020-07-04 09:00 +0200
                Re: Grub cannot see my new hard drive deloptes <deloptes@gmail.com> - 2020-07-04 09:10 +0200

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