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This page provides information about file system problems users and system administrators commonly encounter.

I get: mount: wrong fs type, bad option, bad superblock...

Look at your kernel messages with the dmesg or journalctl command. Most times it will give you much more information about why the mount failed.

Proper mount command looks like this:

mount -t ext4 /dev/sda2 /mnt

The syntax is: mount -t type device dir

I can't mount my Vista-burned CD!

Yep, see bug 313551 - Vista burned UDF volumes won't mount

I was just running along when things started going badly!

Check your logs for error messages, and don't ignore storage related errors; the filesystem may be reacting to other problems. If the errors are not IO/storage related, unmount & run your fsck tool, saving any output for future analysis. You may also wish to take a filesystem metadata image, using e2image, xfs_metadump, or similar.

Everything was fine until I rebooted; now I can't mount!

Did you have a dos partition > 2T? Parted has/had a bug which allowed it to "create" >2T dos partitions, and poke the new partition into the kernel's in-memory tables, but that size can't be stored on disk. So after a reboot, suddenly you are trying to read past the end of the device. Odds are all is not lost; you may be able to create a gpt partition table, with your >2T partition starting in exactly the same place as before, but ending at the proper sector.

My disk is dying, what do I do?

Copy off what you can and buy a new one. If you can't mount and/or copy from it due to IO errors, try one of the dd-rescue type utilities to make an image of the block device, run your repair tool on that, and loopback mount it. You might get lucky.

Have you tried these resources?

Sometimes new information based upon your problem will help be resolved at the following locations: