Running fsck on a Truecrypt Volume

We use an external hard drive encrypted with Truecrypt for backups, and I always forget how to run fsck on it, so I'm just going to document it here. It is actually really simple to do from a Linux terminal.

Since Truecrypt mounts volumes when it decrypts them, it can be a little confusing how to run an fsck (file system check) on them, since you shouldn't run fsck on a mounted filesystem. The solution is to not mount it when you decrypt it, by passing the "--filesystem=none" argument. So if you normally use this command to decrypt the volume:

sudo truecrypt -p secretpassword -k "" --protect-hidden=no /path/to/disk /media/secretspystuff

You would instead use this command to decrypt it without mounting:

sudo truecrypt -p secretpassword -k "" --protect-hidden=no /path/to/disk --filesystem=none

To see where the raw volume is, simply run:

truecrypt -l

And you will get output similar to this:

1: /path/to/disk /dev/mapper/truecrypt1

Now you can run fsck on that how you normally would:

sudo fsck -f /dev/mapper/truecrypt1

Once you are done, you can dismount it with:
sudo truecrypt -d /path/to/disk

or this (which will dismount ALL truecrypt drives):
sudo truecrypt -d

Easy peasy.