Should not recommend to put lockrun files to /tmp

[betelgeuse]

http://docs.engineyard.com/adding-cron-jobs.html

/usr/bin/lockrun --lockfile=/tmp/jobname.lockrun -- sh -c "cd /data/appname/current && rake RAILS_ENV=production some:task"

http://unixwiz.net/tools/lockrun.html

IMPORTANT: Be sure to place the lockfile in a directory that only that user has the rights to, and not in /tmp (as this Tech Tip has previously suggested). If a different user has the ability to write to the directory, s/he could create a symbolic link from the target lockfile to some system file that uses locks the same way, and get the cron job to foul up the locking. 

As the instances are not multi user this is not a big concern but better to go with best practises.