chroot from bash script not working
 

I have a bash script as follows:

for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt/root$i; done
cat << EOF | sudo chroot /mnt/root
update-initramfs -u
grub-install --recheck /dev/sda
grub-install --recheck /dev/sdb
update-grub
EOF

The commands work if entered manually in a terminal, but when the bash script runs, I get the following error message: "unable to execute /usr/sbin/chroot: input output error"

Why?

What are you trying to attempt with those commands? What's their purpose?
Are you aware that
won't execute but will only appear as text on your terminal? So I don't understand the meaning of piping the text output to chroot...

Perhaps you want to pass the commands to a chroot'ed shell?

1) These commands (from "Sudo chroot ... update-grub") are the final part of a system restore-from-backup routine that is run from Live CD. They install grub (and the grub menu) on the two physical disks (sda and sdb). If I don't enter these commands, the restored system will be unbootable, and I would have to install them with "Boot Repair". If I enter the commands manually from the terminal after the restore, they work as desired. But I want to automate the routine.

2) No, I was NOT aware that the commands following the "chroot" command won't execute but will only appear as text. Apparently I misunderstand what the "cat << EOF |" command does. I'm not trying to pipe the text output to chroot. I'm trying to pipe the command input to chroot. (This is what happens when I try to learn bash from forum examples).

3) I tried what "MadeinGermany" has suggested, and it worked.

4) Thank both of you for your help.

Great, you're welcome. Can you mark your thread as "SOLVED" then? ;)

Sorry. I didn't know how to mark it as solved yesterday. I finally found it under "thread tools" today.