After migration our site TecAdmin.net to new VPS (CentOS 6.5) on digital ocean hosting we found that Crontab is not installed on server, When I try to execute crontab -l command, I found following error.
# crontab -l -bash: crontab: command not found
After checking the package of crontab command in our older system, I found it comes from cronie package. So i think to write it for TecAdmin.net readers. Use below command to install it. this will install required dependencies also
Install Crontab
# yum install cronie
Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirror.web-ster.com * updates: mirror.stanford.edu Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package cronie.x86_64 0:1.4.4-12.el6 will be installed --> Processing Dependency: dailyjobs for package: cronie-1.4.4-12.el6.x86_64 --> Running transaction check ---> Package cronie-anacron.x86_64 0:1.4.4-12.el6 will be installed --> Processing Dependency: crontabs for package: cronie-anacron-1.4.4-12.el6.x86_64 --> Running transaction check ---> Package crontabs.noarch 0:1.10-33.el6 will be installed --> Finished Dependency Resolution Dependencies Resolved ================================================================================ Package Arch Version Repository Size ================================================================================ Installing: cronie x86_64 1.4.4-12.el6 base 73 k Installing for dependencies: cronie-anacron x86_64 1.4.4-12.el6 base 30 k crontabs noarch 1.10-33.el6 base 10 k Transaction Summary ========================================================== Install 3 Package(s) Total download size: 114 k Installed size: 220 k Is this ok [y/N]: y Downloading Packages: (1/3): cronie-1.4.4-12.el6.x86_64.rpm | 73 kB 00:00 (2/3): cronie-anacron-1.4.4-12.el6.x86_64.rpm | 30 kB 00:00 (3/3): crontabs-1.10-33.el6.noarch.rpm | 10 kB 00:00 -------------------------------------------------------------------------------- Total 336 kB/s | 114 kB 00:00 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Installing : cronie-1.4.4-12.el6.x86_64 1/3 Installing : crontabs-1.10-33.el6.noarch 2/3 Installing : cronie-anacron-1.4.4-12.el6.x86_64 3/3 Verifying : crontabs-1.10-33.el6.noarch 1/3 Verifying : cronie-anacron-1.4.4-12.el6.x86_64 2/3 Verifying : cronie-1.4.4-12.el6.x86_64 3/3 Installed: cronie.x86_64 0:1.4.4-12.el6 Dependency Installed: cronie-anacron.x86_64 0:1.4.4-12.el6 crontabs.noarch 0:1.10-33.el6 Complete!
How to Add New Job in Crontab
To add a new cron use crontab -e to edit it in editor and add cron as per your requirments. In filesystem crons are saved in file /var/spool/cron/<username>.
# crontab -e
Read below article to read more about Crontab with 20 useful examples.
https://tecadmin.net/crontab-in-linux-with-20-examples-of-cron-schedule/
How to List Jobs in Crontab
To list the job scheduler under crontab, we can use -l command line switch with crontab command. For example to list jobs scheduled for current user
# crontab -l
To view jobs scheduled under other user specify username with -a switch like below.
# crontab -u <username> -l