我有一台装有 ubuntu 20.04 的远程服务器，但我无法使用 livecd 或 VM 控制台
我想将根分区从 /dev/sda2 迁移到 /dev/sda5
我的磁盘配置是：
根@应用程序服务器:~$lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 119G 0 disk
├─sda1 8:1 0 1007K 0 part
├─sda2 8:2 0 79,9G 0 part /
├─sda5 8:5 0 28G 0 part /app
├─sda6 8:6 0 4,7G 0 part /home
├─sda7 8:7 0 953M 0 part /srv
├─sda8 8:8 0 1,9G 0 part /tmp
└─sda9 8:9 0 3,7G 0 part /var
根@应用程序服务器:~#blkid
/dev/sda2: UUID="bda07617-0a2a-44cc-97fa-ff72d1bf45d2" TYPE="ext4" PARTLABEL="Linux filesystem" PARTUUID="45957f98-6bfd-4add-ad05-0b5a604c2423"
/dev/sda1: PARTLABEL="BIOS boot partition" PARTUUID="b33941c4-552c-4ff6-9c95-e7824e7a8102"
/dev/sda5: UUID="e0e56bbd-c2c2-4be5-91c8-02b50fc2f183" TYPE="ext4" PARTLABEL="Linux filesystem" PARTUUID="954341b7-1527-4eb2-ad39-04cb6c84ec72"
/dev/sda6: UUID="db1efe11-5dcf-4f03-a85e-ad379406d484" TYPE="ext4" PARTLABEL="Linux filesystem" PARTUUID="01f1ae61-03ec-405b-8b8a-7732baa74b3f"
/dev/sda7: UUID="2914d504-e0af-4acd-84d8-03e1c7e70136" TYPE="ext4" PARTLABEL="Linux filesystem" PARTUUID="d09bbe8c-5c39-4fdf-8503-fdfcdeb5e4d7"
/dev/sda8: UUID="0e8b5591-df05-4d38-82ca-9e395c098133" TYPE="ext4" PARTLABEL="Linux filesystem" PARTUUID="ae393080-4312-40fc-ba95-c7afc6770a12"
/dev/sda9: UUID="1be50204-6b50-48ec-9da9-cca8a88738eb" TYPE="ext4" PARTLABEL="Linux filesystem" PARTUUID="3e53f06f-764c-42ca-9c77-1c056472eee6"
根@应用程序服务器:~$df -Th
Filesystem Type Size Used Avail Use% Mounted on
udev devtmpfs 932M 0 932M 0% /dev
tmpfs tmpfs 195M 1,7M 193M 1% /run
/dev/sda2 ext4 79G 6,3G 68G 9% /
tmpfs tmpfs 971M 0 971M 0% /dev/shm
tmpfs tmpfs 5,0M 4,0K 5,0M 1% /run/lock
tmpfs tmpfs 971M 0 971M 0% /sys/fs/cgroup
/dev/sda6 ext4 4,6G 87M 4,2G 2% /home
/dev/sda9 ext4 3,6G 2,7G 792M 78% /var
/dev/sda8 ext4 1,8G 148K 1,7G 1% /tmp
/dev/loop0 squashfs 56M 56M 0 100% /snap/core18/2128
/dev/loop1 squashfs 128K 128K 0 100% /snap/bare/5
/dev/sda5 ext4 28G 34M 26G 1% /app
/dev/loop2 squashfs 56M 56M 0 100% /snap/core18/2714
/dev/loop3 squashfs 64M 64M 0 100% /snap/core20/1852
/dev/sda7 ext4 920M 24K 856M 1% /srv
/dev/loop6 squashfs 92M 92M 0 100% /snap/gtk-common-themes/1535
/dev/loop5 squashfs 219M 219M 0 100% /snap/gnome-3-34-1804/72
/dev/loop7 squashfs 66M 66M 0 100% /snap/gtk-common-themes/1515
/dev/loop8 squashfs 51M 51M 0 100% /snap/snap-store/547
/dev/loop9 squashfs 50M 50M 0 100% /snap/snapd/18596
tmpfs tmpfs 195M 28K 195M 1% /run/user/1000
/dev/loop10 squashfs 219M 219M 0 100% /snap/gnome-3-34-1804/77
/dev/loop11 squashfs 46M 46M 0 100% /snap/snap-store/638
/dev/loop12 squashfs 347M 347M 0 100% /snap/gnome-3-38-2004/119
我停止了所有应用程序服务以避免磁盘更改
从 /dev/sda5 删除所有应用程序数据，卸载它
并将所有“/”复制到新的挂载点
root@app-server:~# rm -rf /app/*
root@app-server:~# umount /app
root@app-server:~# mkdir /mnt/newroot
root@app-server:~# mount /dev/sda2 /mnt/newroot
root@kzp-test-gpt:~#ll /mnt/newroot
根@应用程序服务器:~#rsync -aAXv / /mnt/newroot --exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found,/app/*,/home/*,/var/*}
我知道我必须修改 grub 配置和 /etc/fstab
当我在 /mnt/newroot/etc/fstab 中更改 UUID 时，没有任何效果
如何配置 grub 将 /dev/sda5 挂载为根分区
我搜索了 sda 和当前根分区的 UUID，但一无所获
root@app-server:/mnt/newroot/etc/grub.d# grep -ri 'sda' /mnt/newroot/etc/grub.d/
root@app-server:/mnt/newroot/etc/grub.d#grep -ri 'bda07617-0a2a-44cc-97fa-ff72d1bf45d2' /mnt/newroot/etc/grub.d/
root@app-server:/mnt/newroot/etc/grub.d# grep -ri 'sda' /mnt/newroot/etc/default/grub
root@app-server:/mnt/newroot/etc/grub.d#grep -ri 'bda07617-0a2a-44cc-97fa-ff72d1bf45d2' /mnt/newroot/etc/default/grub
我的 grub 文件如下所示：
root@app-server:/mnt/newroot/etc/grub.d#cat /mnt/newroot/etc/default/grub
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n 'Simple configuration'
GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=0
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"
# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480
# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true
# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"
# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"
如何在 grub 中进行更改以及我应该更改哪些配置
旧的根/还是新的/mnt/newroot/
根fstab？有什么帮助吗
答案1
最后我找到了一个解决方案：
运行命令后
rsync -aAXv / /mnt/newroot --exclude={/dev/*,/proc/*,/sys/*,/tmp/*,/run/*,/mnt/*,/media/*,/lost+found,/app/*,/home/*,/var/*}
我们必须编辑新的 fstab/mnt/newroot/etc/fstab
删除包含旧根 UUID 的行，并将包含路径的行从更改/app为/
然后更改 UUID/boot/grub/grub.cfg
sed -i 's/<OLD_ROOT>/<NEW_ROOT>/g' /boot/grub/grub.cfg
我们将稍后修复 grub
重新启动并且 VM 将从新的根分区启动
检查一下df -h /
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 28G 12G 15G 45% /
接下来通过 fstab 删除旧的根分区
并更新 grub
grub-install /dev/sda
update-grub
reboot now