[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Boot from 4TB USB jhard drive

From: Emilio Lazo Zaia
Subject: Re: Boot from 4TB USB jhard drive
Date: Sun, 20 Mar 2016 02:08:43 -0430
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:44.0) Gecko/20100101 Icedove/44.0

On 20/03/16 00:35, Andrei Borzenkov wrote:
Create rescue image that can be used to boot off CD/USB

pkgdatadir=$PWD ./grub-mkrescue -d grub-core -o /tmp/grub.iso

This creates ISO image suitable for both CD and HDD boot. If using USB
stick, just dd this image on full stick. When booting from it, you will
end in GRUB command prompt.
Dumped into a USB stick...
Check what

ls -l
in GRUB CLI says. What sector size GRUB detects for your disk? Does GRUB
see partitions on your disk? Do they look reasonable (size, offset)? If
yes, try
It says "Device hd2: No known filesystem detected - Sector size 4096B - Total size 3906984960KiB"

Partitions are not detected! In the previous test (GRUB 2.00-7) it doesn't show the sector size but the sector size it detects is 512B because of total sectors and partition offsets. In that test, ls -l says:

Device hd2: No known filesystem detected - Total size 7813969920
    Partition hd2,gpt2: No known ... - Starts at 2048 ...
    Partition hd2,gpt1: No known ... - Starts at 64 ...

Total size of 7813969920 sectors with 512 bytes per sector is also 3906984960KiB. Partition 1 starts at sector 64 (assuming 512B sectors) is the same as it starts at sector 8 (4096B sectors, as gpart shows). The same applies to partition 2, which starts at sector 2048 on 512B units, or 256 on 4096B units.

insmod lvm
ls -l

again. Does GRUB detect LVs?
Nein. It doesn't detect LVs with the iso hybrid image I dumped into an USB stick, but it detect LVs and load kernel with GRUB 2.00-7 installed on laptop's hard drive.
Do you have serial port (RS-2323) on your system and another system that
can be used to connect to serial port? This would make capturing output
much easier.
I'm sorry, I don't have serial ports.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]