$ ls /var/lock
dmraid/ lockdev/ lvm/ subsys/$ locate mtab
/etc/mtab
/etc/mtab.fuselock
/home/user/.local/share/akonadi/db_data/akonadi/pimitemtable.frm
/home/user/.local/share/akonadi/db_data/akonadi/pimitemtable.ibd
/usr/lib/python2.7/symtable.py
/usr/lib/python2.7/symtable.pyc
/usr/lib/python2.7/symtable.pyo
/var/lib/nfs/rmtab