how do you run a filesystem check?

edit

To perform a filesystem check, you have to use the tool fsck.

# fsck /dev/sda2

Keep in mind, the partition must be unmounted. Use

# umount /dev/sda2

to unmount the partition. However, in some cases, such as if you want to check your `/` partition (your root partition), you have to either use a Live CD of Fedora or perform the fsck at boot. To achieve that, execute

# cat /etc/fstab

The output of that should be close to:

#
# /etc/fstab
# Created by anaconda on Mon Apr 14 19:56:10 2014
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
#UUID=6b266543-a497-44de-981f-ee460b85590a /                       ext4    defaults        1 0
UUID=48ce0f9f-eee1-4f72-b90e-1a28e6a83c8e /boot                   ext4    defaults        1 0
UUID=D58E-1C9A          /boot/efi               vfat    umask=0077,shortname=winnt 0 0
UUID=448774a1-05f9-47e6-9fad-ac5ac4e10b64 /home                   ext4    defaults        1 1 #Note the last 1
UUID=a60856f9-2247-4d13-b4a8-a9e2ecd91aa4 /var                    ext4    defaults        1 0
UUID=0a0ff8de-5395-469d-8e51-a7982d4a3645 swap                    swap    defaults        0 0

The last 1 on the line mounting /home signifies that it will be checked during boot. After it is done, I suggest you keep checking the partition, but if wanted, change to a 0. Honesly, I am not performing important tasks on this machine, so I don't fsck any of my partitions.

HTH.

Note: All of this is done from a terminal