GRUB is used to manage booting into multiple operating systems and to specify boot options for each operating system.
GRUB could get corrupted or replaced in events like when installing
Microsoft Windows, making you unable to load your other installed operating systems.
Boot information is still available in
Linux's installation disk and
GRUB could be re-created from the available boot information.
Linuxusing Live CD / USB Drive.
Live CDmode if available.
Ubuntu installer, click on the
Try Ubuntu button.
Live CD mode available, press
<f2> keys to get to the terminal. For
Ubuntu, the default username is
ubuntu and the password is empty (just press enter at the password prompt).
Linuxpartition with working
$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT loop0 7:0 0 1.9G 1 loop /rofs loop1 7:1 0 89.3M 1 loop /snap/core/6673 loop2 7:2 0 53.7M 1 loop /snap/core18/941 sda 8:0 0 20G 0 disk └─sda1 8:1 0 20G 0 part sr0 11:0 1 2G 0 rom /cdrom
$ mkdir tmp
Linuxpartition to the newly created temporary directory.
$ sudo mount /dev/sda1 tmp/
/procfolders folders to the
Linuxpartitions' mount point.
$ sudo mount --bind /dev tmp/dev $ sudo mount --bind /proc tmp/proc
$ sudo chroot tmp/ [email protected]:/#
GRUBbootloader from existing configuration files.
[email protected]:/# grub-install /dev/sda Installing for i386-pc platform. Unknown device "/dev/sda1": No such device Unknown device "/dev/sda1": No such device Unknown device "/dev/sda1": No such device Unknown device "/dev/sda1": No such device Unknown device "/dev/sda1": No such device Unknown device "/dev/sda1": No such device Installation finished. No error reported.
[email protected]:/# exit exit
$ sudo poweroff
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