我有一台旧上网本，我想在上面安装 Lubuntu。我安装了 Lubuntu，安装成功。但是安装后重新启动时，系统无法启动。它会显示no Bootable disk found。我还尝试使用 boot-repair 修复启动。仍然没有成功。以下是 Boot-repair 的 pastebin 信息
boot-repair-4ppa125 [20200901_0535]
============================= Boot Repair Summary ==============================
Recommended repair: ____________________________________________________________
The default repair of the Boot-Repair utility will reinstall the grub2 of
sda1 into the MBR of sda.
Additional repair will be performed: unhide-bootmenu-10s
Unhide GRUB boot menu in sda1/etc/default/grub
========================= Reinstall the grub2 of sda1 ==========================
grub-install --version
grub-install (GRUB) 2.04-1ubuntu26.2
==> Reinstall the GRUB of sda1 into the MBR of sda
grub-install /dev/sda
Installing for i386-pc platform.
Installation finished. No error reported.
chroot /media/lubuntu/58a4b883-7c41-491c-bca4-0e2d885513aa update-grub
Sourcing file `/etc/default/grub'
Sourcing file `/etc/default/grub.d/init-select.cfg'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.4.0-42-generic
Found initrd image: /boot/initrd.img-5.4.0-42-generic
Found memtest86+ image: /boot/memtest86+.elf
Found memtest86+ image: /boot/memtest86+.bin
File descriptor 63 (pipe:[73155]) leaked on lvs invocation. Parent PID 14999: /bin/sh
Unhide GRUB boot menu in sda1/boot/grub/grub.cfg
Boot successfully repaired.
You can now reboot your computer.
============================ Boot Info After Repair ============================
=> Grub2 (v2.00) is installed in the MBR of /dev/sda and looks at sector 1 of
the same hard drive for core.img. core.img is at this location and looks
for (,msdos1)/boot/grub. It also embeds following components:
modules
---------------------------------------------------------------------------
fshelp ext2 part_msdos biosdisk
---------------------------------------------------------------------------
=> Syslinux MBR (5.00 and higher) is installed in the MBR of /dev/sdb.
sda1: __________________________________________________________________________
File system: ext4
Boot sector type: -
Boot sector info:
Operating System: Ubuntu 20.04.1 LTS
Boot files: /boot/grub/grub.cfg /etc/fstab /etc/default/grub
/boot/grub/i386-pc/core.img
sdb1: __________________________________________________________________________
File system: vfat
Boot sector type: SYSLINUX 6.04
Boot sector info: Syslinux looks at sector 32800 of /dev/sdb1 for its
second stage. The integrity check of Syslinux failed.
No errors found in the Boot Parameter Block.
Operating System:
Boot files: /boot/grub/grub.cfg /syslinux.cfg
/efi/BOOT/grubx64.efi /efi/BOOT/mmx64.efi /ldlinux.sys
================================ 1 OS detected =================================
OS#1: Ubuntu 20.04.1 LTS on sda1
============================ Architecture/Host Info ============================
CPU architecture: 64-bit
Live-session OS is Ubuntu 64-bit (Ubuntu 20.04.1 LTS, focal, x86_64)
===================================== UEFI =====================================
This live-session is not in EFI-mode.
EFI in dmesg.
[ 71.188831] systemd[1]: Condition check resulted in Store a System Token in an EFI Variable being skipped.
============================= Drive/Partition Info =============================
Disks info: ____________________________________________________________________
sda : notGPT, no-BIOSboot, has-noESP, not-usb, not-mmc, has-os, 2048 sectors * 512 bytes
Partitions info (1/3): _________________________________________________________
sda1 : is-os, 64, apt-get, grub-pc , grub2, grub-install, grubenv-ok, update-grub, farbios
Partitions info (2/3): _________________________________________________________
sda1 : isnotESP, fstab-without-efi, no-nt, no-winload, no-recov-nor-hid, no-bmgr, notwinboot
Partitions info (3/3): _________________________________________________________
sda1 : not-sepboot, with-boot, fstab-without-boot, not-sep-usr, with--usr, fstab-without-usr, std-grub.d, sda
fdisk -l (filtered): ___________________________________________________________
Disk sda: 465.78 GiB, 500107862016 bytes, 976773168 sectors
Disk identifier: 0x975662f8
Boot Start End Sectors Size Id Type
sda1 2048 976768064 976766017 465.8G 83 Linux
Disk sdb: 14.62 GiB, 15682240512 bytes, 30629376 sectors
Disk identifier: 0x0217ce81
Boot Start End Sectors Size Id Type
sdb1 * 2048 30629375 30627328 14.6G c W95 FAT32 (LBA)
Disk zram0: 247.2 MiB, 259198976 bytes, 63281 sectors
Disk zram1: 247.2 MiB, 259198976 bytes, 63281 sectors
Disk zram2: 247.2 MiB, 259198976 bytes, 63281 sectors
Disk zram3: 247.2 MiB, 259198976 bytes, 63281 sectors
parted -lm (filtered): _________________________________________________________
sda:500GB:scsi:512:512:msdos:ATA ST3500418AS:;
1:1049kB:500GB:500GB:ext4::;
sdb:15.7GB:scsi:512:512:msdos:SanDisk Cruzer Blade:;
1:1049kB:15.7GB:15.7GB:fat32::boot, lba;
zram3:259MB:unknown:4096:4096:loop:Unknown:;
1:0.00B:259MB:259MB:linux-swap(v1)::;
zram1:259MB:unknown:4096:4096:loop:Unknown:;
1:0.00B:259MB:259MB:linux-swap(v1)::;
zram2:259MB:unknown:4096:4096:loop:Unknown:;
1:0.00B:259MB:259MB:linux-swap(v1)::;
zram0:259MB:unknown:4096:4096:loop:Unknown:;
1:0.00B:259MB:259MB:linux-swap(v1)::;
blkid (filtered): ______________________________________________________________
NAME FSTYPE UUID PARTUUID LABEL PARTLABEL
sda
└─sda1 ext4 58a4b883-7c41-491c-bca4-0e2d885513aa 975662f8-01
sdb
└─sdb1 vfat A6BD-F480 0217ce81-01 LUBUNTU
zram0
zram1
zram2
zram3
df (filtered): _________________________________________________________________
Avail Use% Mounted on
sda1 429.4G 1% /media/lubuntu/58a4b883-7c41-491c-bca4-0e2d885513aa
sdb1 12.9G 11% /cdrom
Mount options: __________________________________________________________________
sda1 rw,nosuid,nodev,relatime
sdb1 ro,noatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro
====================== sda1/boot/grub/grub.cfg (filtered) ======================
Ubuntu 58a4b883-7c41-491c-bca4-0e2d885513aa
Ubuntu, with Linux 5.4.0-42-generic 58a4b883-7c41-491c-bca4-0e2d885513aa
### END /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_uefi-firmware ###
========================== sda1/etc/fstab (filtered) ===========================
# <file system> <mount point> <type> <options> <dump> <pass>
UUID=58a4b883-7c41-491c-bca4-0e2d885513aa / ext4 defaults 0 1
======================= sda1/etc/default/grub (filtered) =======================
GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
==================== sda1: Location of files loaded by Grub ====================
GiB - GB File Fragment(s)
0.000980377 = 0.001052672 boot/grub/grub.cfg 1
130.139995575 = 139.736756224 boot/grub/i386-pc/core.img 1
1.379024506 = 1.480716288 boot/vmlinuz 2
1.379024506 = 1.480716288 boot/vmlinuz-5.4.0-42-generic 2
1.379024506 = 1.480716288 boot/vmlinuz.old 2
1.457019806 = 1.564463104 boot/initrd.img 3
1.457019806 = 1.564463104 boot/initrd.img-5.4.0-42-generic 3
1.457019806 = 1.564463104 boot/initrd.img.old 3
===================== sda1: ls -l /etc/grub.d/ (filtered) ======================
-rwxr-xr-x 1 root root 17123 Jul 31 00:34 10_linux
-rwxr-xr-x 1 root root 42128 Jul 31 00:34 10_linux_zfs
-rwxr-xr-x 1 root root 12894 Jul 31 00:34 20_linux_xen
-rwxr-xr-x 1 root root 12059 Jul 31 00:34 30_os-prober
-rwxr-xr-x 1 root root 1424 Jul 31 00:34 30_uefi-firmware
-rwxr-xr-x 1 root root 214 Jul 31 00:34 40_custom
-rwxr-xr-x 1 root root 216 Jul 31 00:34 41_custom
====================== sdb1/boot/grub/grub.cfg (filtered) ======================
Start Lubuntu
Start Lubuntu (safe graphics)
OEM install (for manufacturers)
Boot from next volume
UEFI Firmware Settings
========================= sdb1/syslinux.cfg (filtered) =========================
DEFAULT loadconfig
LABEL loadconfig
CONFIG /isolinux/isolinux.cfg
APPEND /isolinux/
==================== sdb1: Location of files loaded by Grub ====================
GiB - GB File Fragment(s)
?? = ?? boot/grub/grub.cfg 1
================== sdb1: Location of files loaded by Syslinux ==================
GiB - GB File Fragment(s)
?? = ?? syslinux.cfg 1
?? = ?? ldlinux.sys 1
=============================== StdErr Messages ================================
File descriptor 63 (pipe:[73155]) leaked on lvs invocation. Parent PID 3014: /bin/bash
我做错了什么？我该如何解决这个问题？