Write a note on cron files.

35.Write a note on cron files.

Ans.

1. ‘cron’ is a daemon that executes commands according to a preset schedule that a user defines.

2. It wakes up every minute and checks all cron files to see what jobs need to be run at that time.

3. cron files can be set up by user or the system administrator to take care of system task.

4. Users edit their crontab files by telling cron what programs they’d like to run automatically and how often they’d like to run them.

5. User crontab files are stored in ‘/var/spool/cron’. They are named after the user they belong to.

6. System cron files are stored in the following subdirectories of the /etc directory:

• cron.d

• cron.daily

• cron.hourly

• cron.monthly

• cron.weekly

7. crontab in the /etc directory is sort of the master control file set up to run all the scripts.

8. By default, a file in cron.d called ‘sysstat’ runs a system activity accounting tool every 10 minutes, 24x7.