I'm getting an some kind of error at the VGA console when I make a configuration file for grub (at least I think it's an error), with

grub-mkconfig -o /boot/grub/grub.cfg

I tried to redirect stderr and stdout into a file named ~/grub_error like this:

grub-mkconfig -o /boot/grub/grub.cfg 2>&1 ~/grub_error

However, what I though to be an error, still printed to the screen (~/grub_error had stdout redirected to it, so I don't think I made a syntax error).

I also noticed that when I run grub-mkconfig in a terminal in an X session, the "error" that shows up on the VGA console doesn't show up. Is there something else I should be redirecting, because the error seemed pretty serious, something along the lines of "...could lead to file system corruption". It may be worth noting that i'm using a BIOS machine with GPT, so I have a bios_boot partition, and the error said something about /dev/sda1 (my bios_boot partition) not having and ext4 file system (which it doesn't and shouldn't).

[ 2709.836576] EXT4-fs (sda1): VFS: Can't find ext4 filesystem
[ 2709.839402] EXT4-fs (sda1): VFS: Can't find ext4 filesystem
[ 2709.841988] EXT4-fs (sda1): VFS: Can't find ext4 filesystem
[ 2709.846191] XFS (sda1): Invalid superblock magic number
[ 2709.850344] FAT-fs (sda1): invalid media value (0xe2)
[ 2709.850806] FAT-fs (sda1): Can't find a valid FAT filesystem
[ 2709.853194] FAT-fs (sda1): invalid media value (0xe2)
[ 2709.853781] FAT-fs (sda1): Can't find a valid FAT filesystem
[ 2709.855905] ntfs: (device sda1): is_boot_sector_ntfs(): Invalid boot sector checksum.
[ 2709.855913] ntfs: (device sda1): read_ntfs_boot_sector(): Primary boot sector is invalid.
[ 2709.856367] ntfs: (device sda1): read_ntfs_boot_sector(): Mount option errors=recover not used. Aborting without trying to recover.
[ 2709.856902] ntfs: (device sda1): ntfs_fill_super(): Not an NTFS volume.
[ 2709.859565] VFS: Can't find a Minix filesystem V1 | V2 | V3 on device sda1.
[ 2709.861950] hfsplus: unable to find HFS+ superblock
[ 2709.863881] ufs: You didn't specify the type of your ufs filesystem

               mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...

               >>>WARNING<<< Wrong ufstype may corrupt your filesystem, default is ufstype=old
[ 2709.867491] ufs: ufs_fill_super(): bad magic number
[ 2709.872393] hfs: can't find a HFS filesystem on dev sda1
  • You're asking two different things. You should split the second one into another question.
    – h0tw1r3
    Jul 27, 2016 at 2:50
  • Sorry if it's unclear, but i'm asking how to redirect all of the output of the command, then I can ask a question regarding that output, the rest of the question is background.
    – Vityou
    Jul 27, 2016 at 2:53

1 Answer 1


You redirect stderr to stdout, but you also need to redirect stdout itself. You're just missing the > and the order of redirection is very important.

grub-mkconfig -o /boot/grub/grub.cfg >~/grub_error 2>&1


As for the difference between the console and terminal output (and seemingly lack of redirection on the console), that usually indicates a kernel message. Open another terminal and type dmesg -w. Then run the program or script again. You should see the messages that were not redirected in the console, or absent in the terminal, output by the dmesg command.

  • That didn't redirect anything into the file.
    – Vityou
    Jul 27, 2016 at 2:51
  • 1
    updated answer. the order is important.
    – h0tw1r3
    Jul 27, 2016 at 2:54
  • That seemed to work, but I still got the "error" message. So I guess it's not stdout or stderr.
    – Vityou
    Jul 27, 2016 at 2:57
  • That was it, I added the error to the question, or should I ask a separate question?
    – Vityou
    Jul 27, 2016 at 3:02
  • Let us continue this discussion in chat.
    – h0tw1r3
    Jul 27, 2016 at 3:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.