Should not recommend to put lockrun files to /tmp

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

``` bash
/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.