$ dlocate mkfs.ext3
e2fsprogs: /sbin/mkfs.ext3
e2fsprogs: /usr/share/man/man8/mkfs.ext3.8.gz

$ dlocate mke2fs
e2fsprogs: /sbin/mke2fs
e2fsprogs: /usr/share/man/man8/mke2fs.8.gz
e2fsprogs: /usr/share/man/man5/mke2fs.conf.5.gz
e2fsprogs: /etc/mke2fs.conf

run "sudo apt-get install dlocate" and then "updatedb"

then you can use dlocate effectively