一次Linux迁移的记录

笔记本有一个2280和一个2240硬盘位，因此要把原来2280的盘迁移到2240的上。
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硬盘上只有两个分区：UEFI引导分区（FAT32）和 / 挂载点（EXT4），因此迁移就比较容易

步骤

具体来说，

1. 同时挂载原硬盘和新硬盘，我这次是在原硬盘上的系统里挂载了新硬盘在/mnt/，并非使用live CD等，不过原理大同小异。
   这里原硬盘是/dev/nvme1n1，新硬盘是/dev/nvme0n1

2. 分区。使用了图形化的gparted，仿照原硬盘在新硬盘上分出300MB的UEFI引导分区/dev/nvme0n1p1和剩余的 / 挂载点/dev/nvme0n1p3，注意要把引导区的boot标志勾选。
   
   

3. 复制原硬盘的 / 到新硬盘的 / 挂载点/dev/nvme0n1p3，注意要忽略：

   '/dev/*','/proc/*','/sys/*','/tmp/*','/run/*','/mnt/*','/lost+found/*','/media/*'

   这些文件。
   我用的是rsync，具体命令见后面脚本。dd等命令更底层，还要涉及到文件系统resize的问题，rsync就不会。

4. 挂载 /dev /sys/ … 等关键目录，否则无法进入新系统。这相当于新硬盘的系统和老硬盘的系统公用这些路径，为后面chroot准备。

      mount --bind /dev/ /mnt/dev/
      mount --bind /sys/ /mnt/sys/
   # 具体命令见后面脚本。

   同时也要挂载新硬盘的引导分区到新硬盘的/boot/efi，从而能安装grub引导。

   mount /dev/nvme0n1p1 /mnt/boot/efi

5. 进入chroot环境。
   chroot就是更改当前Linux的root目录，此时相当于在新硬盘的系统中执行命令。

   chroot /mnt

6. 修改/etc/fstab里的UUID为当前新盘的UUID。grub是靠UUID找对应的盘的，这也是全盘克隆无法启动的原因，因为两个盘的UUID不一样。

   blkid /dev/nvme0n1p3 # 查看UUID

7. 修复grub引导

   grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader=Manjaro --recheck

   切记这是在chroot环境，因此路径是/boot/efi。
   最后写入grub

   grub-update

   在执行grub-update前可以安装os-prober，这样grub-update能检测所有硬盘中的引导区。当然现在电脑里有两个一样的Linux，需要把老的硬盘卸载、插入新的硬盘（比如win10）的，再进入新的Linux安装一遍os-prober后执行grub-update。

现在新的Linux就好了。

grub2

grub2可以安装主题进行美化，我用的是Gorgeous-GRUB里挑选的Virtuaverse，执行安装脚本即可。

自动脚本

脚本对于单个或多个挂载点的情况可以处理，至于有逻辑分区等等复杂的情况不知道行不行。

#!/bin/bash

# Regular Colors
BLACK='\033[0;30m'
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
BLUE='\033[0;34m'
PURPLE='\033[0;35m'
CYAN='\033[0;36m'
WHITE='\033[0;37m'

# Bold Colors (加粗)
BBLACK='\033[1;30m'
BRED='\033[1;31m'
BGREEN='\033[1;32m'
BYELLOW='\033[1;33m'
BBLUE='\033[1;34m'
BPURPLE='\033[1;35m'
BCYAN='\033[1;36m'
BWHITE='\033[1;37m'

# Underlined Colors (下划线)
UBLACK='\033[4;30m'
URED='\033[4;31m'
UGREEN='\033[4;32m'
UYELLOW='\033[4;33m'
UBLUE='\033[4;34m'
UPURPLE='\033[4;35m'
UCYAN='\033[4;36m'
UWHITE='\033[4;37m'

# Background Colors (背景色)
BG_BLACK='\033[40m'
BG_RED='\033[41m'
BG_GREEN='\033[42m'
BG_YELLOW='\033[43m'
BG_BLUE='\033[44m'
BG_PURPLE='\033[45m'
BG_CYAN='\033[46m'
BG_WHITE='\033[47m'

# No Color
NC='\033[0m'

# ===========================


efi_mnt=/boot/efi	# constant
mnt=/mnt/targetOS	# constant
mnt_source=/mnt/sourceOS	# constant

efi=0
declare -a from
declare -a to
declare -a point

ischroot=0

function error() {
    echo -e  " ${BRED}ERROR:$ 1\nSee '--help'${NC} "
    exit 1
}

if [ "$UID" -ne 0 ]; then
    error "This script must be run as root."
    exit 1
fi

function color_echo() {
    local input="$1"
	# Replace words with colored words
    for colori in "${!from[@]}"; do
	    input=" ${input//$ {from[colori]}/ ${BRED}$ {from[colori]}${NC}}"
	    input=" ${input//$ {to[colori]}/ ${BGREEN}$ {to[colori]}${NC}}"
		# input=" ${input//$ {point[ $i]}/$ {BCYAN} ${point[$ i]}${NC}}"
    done
    input=" ${input//$ {efi}/ ${BBLUE}$ {efi}${NC}}"
    input=" ${input//$ {mnt}/ ${BYELLOW}$ {mnt}${NC}}"
    input=" ${input//$ {mnt_source}/ ${BPURPLE}$ {mnt_source}${NC}}"
    input=" ${input//$ {efi_mnt}/ ${BCYAN}$ {efi_mnt}${NC}}"
    echo -e -n "$input"
}

# read arguments
while [[ "$#" -gt 0 ]]; do
    case $1 in
		--chroot)
		    ischroot=1
		    shift 1
			;;
		--efi)
		    efi="$2"
		    shift 2
			;;
		--move)
		    if [[ "$#" -le 3 ]]; then
			    error "--move requires 3 arguments"
		    fi
		    point+=("$2")
		    from+=("$3")
		    to+=("$4")
		    shift 4
			;;
		--help)
		    echo sudo $0 --efi "{efi} [--move / {from} {to} [--move {point} {from} {to} [...]]]"
		    echo
		    echo "{efi} {from} {to} are partitions like /dev/nvme0n1"
		    echo "{point} are mount points of the corresponding partition"
		    echo "note that the first mount point given must be '/'"
		    exit 0
			;;
		*)
		    error "Unknown parameter passed: $1"
			;;
    esac
done

function run_cmd() {
    local cmd="$1"
    echo -n -e " ${BCYAN} >$ {NC}"
    color_echo "$2"
    echo -n -e " ${BG_WHITE}$ {UBLACK}[Y/n]${NC}:"
    read -r response < /dev/tty
    if [[ " $response" == "" || "$ response" == "y" || "$response" == "y" ]]; then
	    eval "$cmd"
    else
	    if [ -z "$3" ]; then
		    echo -e " ${BRED}Command aborted.$ {NC}"
	    else
		    eval "$3"
	    fi
    fi
}

get_uuid() {
    local device="$1"
	# Use blkid to fetch the UUID
    local uuid= $(blkid "$ device" | sed -n 's/.* UUID="\([^"]*\)".*/\1/p')
	# Check if the UUID is empty
    if [[ -z "$uuid" ]]; then
	    echo "No UUID found for device $device"
	    return 1
    fi
    echo "$uuid"
}

if [[ ischroot -eq 0 ]]; then
	# check valid
    if [[ -z "$efi" ]]; then
	    error "No EFI device assigned"
    fi
    if [ ${#from[@]} -eq 0 ]; then
	    error "--move missing"
    fi
    if [[ ${point[0]} != "/" ]]; then
	    error "First mouont point must be '/'"
    fi
	# output arguments
    color_echo "EFI partition: $efi\n"
    for i in "${!from[@]}"; do
	    color_echo "Move from: ${from[$ i]} (mount point ${BCYAN}$ {point[ $i]}$ {NC}) to: ${to[$ i]}\n"
    done
	# double check from uesr
    run_cmd "" "Continue?" "exit"

    mkdir -p $mnt 2> /dev/null
    mkdir -p $mnt_source 2> /dev/null

    for i in "${!from[@]}"; do
	    run_cmd <<-EOF "
	    mount ${to[$ i]} ${mnt}
	    mount ${from[$ i]} ${mnt_source}
		" "Mounting ${to[$ i]} to ${mnt},$ {from[ $i]} to$ {mnt_source}"
	    EOF

	    run_cmd <<-EOF "
	    rm -rf $mnt/*
		" "Clearing $mnt (where$ {to[$i]} is mounted)"
	    EOF

	    if [[ $i -eq 0 ]]; then
		    run_cmd <<-EOF "
		    rsync -aAX --stats $mnt_source/$ mnt/ --exclude={'/dev/*','/proc/*','/sys/*','/tmp/*','/run/*','/mnt/*','/lost+found/*','/media/*'}
			" "Copying from ${from[$ i]} to $mnt (where$ {to[$i]} is mounted) via rsync, with /dev/,/proc/,etc. excluded"
		    EOF
	    else
		    echo $i iii
		    run_cmd <<-EOF "
		    rsync -aAX --stats $mnt_source/$ mnt/
			" "Copying from ${from[$ i]} to $mnt (where$ {to[$i]} is mounted) via rsync"
		    EOF
	    fi


	    umount $mnt 2> /dev/null # always unmount
	    umount $mnt_source 2> /dev/null # always unmount
    done

    run_cmd <<-EOF "
    for i in "\${!from[@]}"; do
	    mkdir -p \ ${mnt}\$ {point[\$i]}
	    mount \ ${to[\$ i]} \ ${mnt}\$ {point[\$i]}
    done" "Mount all partitions to $mnt"
    EOF

    run_cmd <<-EOF "
    mount ${from[0]}$ mnt_source
    for dir in /dev /dev/pts /proc /sys /sys/firmware/efi/efivars /run; do
	    color_echo \"mounting $mnt_source\$ dir to $mnt\$ dir;\\n\"
	    mount --bind $mnt_source\$ dir $mnt\$ dir
    done" "Mounting necessary points to $mnt from source OS"
    EOF

    run_cmd <<-EOF "
    mount $efi$ mnt$efi_mnt
	" "Mounting EFI partition in $mnt$ efi_mnt"
    EOF

    run_cmd <<-EOF "
    chroot $mnt /bin/bash$ (realpath $0) --chroot$ *
	" "Doing chroot (This will enter chroot environment)"
    EOF

    run_cmd <<-EOF "
    echo Press ENTER again to reboot!
    read
    reboot
	" "Ready to reboot"
    EOF

else
    echo "I am in chroot environment now!"
    old_uuid= $(get_uuid$ from)
    uuid= $(get_uuid$ to)
    color_echo "UUID of (from) $from is$ old_uuid"
    echo
    color_echo "UUID of (to) $to is$ uuid"
    echo

    run_cmd <<-EOF "
    sudo sed -i 's@ $old_uuid@$ uuid@g' /etc/fstab
	" "Now change UUID in /etc/fstab:\nreplace $old_uuid to$ uuid"
    EOF

    run_cmd <<-EOF "
    grub-install --target=x86_64-efi --efi-directory=$efi_mnt --bootloader=Manjaro --recheck
	" "Intalling GRUB"
    EOF

    run_cmd <<-EOF "
    update-grub
	" "Updating GRUB"
    EOF

    run_cmd <<-EOF "
    exit
	" "exit chroot!"
    EOF

fi

echo "Quitting."

脚本还有待测试。