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Editor to share with you how to achieve crontab implementation results in linux did not notify users by sending mail, I believe most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

Symptom

A crontab task is set on a centos7 host, but after running mail when the time comes, it prompts No mail, that is, cron did not send an email to the user to notify the user of the execution result of the task

Investigation process

Check the crontab log

The logs of centos are managed by systemd, so you can view the related logs through systemctl.

Journalctl _ COMM=crond-- since=today

Or use root to view the log / var/log/cron

Sudo cat / var/log/cron | grep-v'/ usr/local/qcloud/stargate/admin/start.sh'

Eventually we will see a line in the log that prompts Jun 22 00:50:19 localhost CROND [21181]: (lujun9972) MAIL (mailed 102 bytes of output but got status 0x004b#012)

That is, the mail failed to be sent.

Check the mail log

Check the / var/log/maillog log and you will find that the log prompts Jun 22 00:50:19 localhost postfix/sendmail [21403]: fatal: parameter inet_interfaces: no local interface found for:: 1

In other words, the mail prompt cannot find the corresponding network card for the address of IPV6 on the host:: 1

Solution method

After commenting out the address corresponding to:: 1 in / etc/hosts, it is found that the error message of mail has become postfix/postdrop [5487]: warning: unable to look up public/pickup: No such file or directory

After searching, you only need to create the missing file and restart the postfix service.

Sudo mkfifo / var/spool/postfix/public/pickupsudo chown postfix:postdrop pickupsystemctl restart postfix.service above are all the contents of the article "how to achieve crontab execution results in linux without notifying users by sending mail". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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