A start job is running for /boot

"A start job is running for /boot"

This line was the error message I got.

The booting process was very slow, i.e. more than five minutes.

I don't know if this is the fix:

http://askubuntu.com/questions/616757/a-start-job-is-running-for-etc-rc-local-compatibility-how-to-fix


#### The /etc/rc.local file:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
fstrim -v /
fstrim -v /home
fstrim -v /boot
exit 0
My current system is Debian Jessie. Maybe I need to downgrade my Debian Linux system.