Hi mutsuhito,

may I assume that you have checked that /dev/sda5 is truly the device for your "home" file system and that it's an XFS file system? You might want to double-check by looking into /etc/fstab.

Like eblock already asked - do you recall what process it was that you needed to kill in order to change your username? Assuming that you called "usermod -l newusername oldusername", it'd be interesting to know what process might be interfering with that operation.

Also, did you shut down your machine properly for the reboot? Or was is a simple power cycle?

Just for the records - if it was all about the directory name, you might have simply changed that using "usermod -m -d /home/newdirname username"