MAILTO=goeltushar4391234#gmail.com
54 1 * * * pg_dump -U postgres db_name > ~/backup/bck.bak
* * * * * ~/backup/bck.bak
I am using the above cron job in PostgreSQL. The backup is created successfully, but mail is not coming. Moreover, I am confused from which ID I will receive mail. How can I fix this?
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I am trying to run a crontab with the expression given below. But i am getting bad minute error.
This is for a Linux Server.
0/5 * * * * /home/cdh_infa_user/data/pladmin/MyLinuxAgent/apps/Data_Integration_Server/data/scripts/Secureagent.sh
Do i need to install crontab? Please guide
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To run cron every 5 minutes you need to add command like this:
*/5 * * * * /home/cdh_infa_user/data/pladmin/MyLinuxAgent/apps/Data_Integration_Server/data/scripts/Secureagent.sh
To run cron at 5 a clock you need record like this:
0 5 * * * /home/cdh_infa_user/data/pladmin/MyLinuxAgent/apps/Data_Integration_Server/data/scripts/Secureagent.sh
I'm using shared cPanel hosting.
When I enter the following cron job command it works:
*/5 * * * * /usr/bin/mysqldump -u user -p'pazzword' my_db > /backup/database.sql
But when I try to add date stamp to the file name, it doesn't generate .sql files.
*/5 * * * * /usr/bin/mysqldump -u user -p'pazzword' my_db > /backup/database_$(date +"%Y_%m_%d").sql
I can't find cron job error logs, have I made an error in my command?
Okay. Finally I managed to fix the problem.
You need to escape % with **** .
So the working cron job command will look like this:
*/5 * * * * /usr/bin/mysqldump -u user -p'pazzword' my_db > /backup/database_$(date +"\%Y_\%m_\%d").sql
I am new to Linux and Ubuntu and I seldom have to use it. I am trying to make this PHP script to run every minute using cron, but firstly I wanted to make some tests.
I created an empty file at /var/www/html/ called test. I ran on terminal:
sudo crontab -e
And added this line:
0 * * * * rm /var/www/html/test
Then saved it and exited. It said "Installing new Crontab"
Nothing happened. Then I created a file bfile.sh that contained:
#!/bin/sh
rm /var/www/html/test
and added the following to crontab:
0 * * * * bash /var/www/html/bfile.sh
Still nothing happened.
What do I have to do to see anything happening from crontab? By the way I checked and the service is running
0 * * * * basically says "run this at 0th minute of every hour."
If you need cron to run your command every minute do * * * * *.
0 * * * * runs once every 1 hour. If you want to run every minute it should be */1 * * * *
You can also check the /var/log/cron file for any errors
I have this line in crontab:
* * * * * /var/www/dir/sh/mysql_dumb.sh | mail -s "mysql_dump" example#mail.com
(every minute only a sample)
So, all works fine, but the email is empty.
UPDATE:
The output from mysql_dumb.sh is a *.sql file and they save the file in a directory.
How can I send a copy (*.sql file) from this output -> mysql_dumb.sh to my email?
mysql_dumb.sh:
#!/bin/bash
PATH=/usr/bin:/bin
SHELL=/bin/bash
/usr/bin/mysqldump -u USER -pPASS DATABASE > /var/www/dir/backup/backup_DB_`date +%d_%m_%Y`.sql
If the script is reporting errors, they may be going to stderr, but you're only redirecting stdout. You can redirect stderr by adding 2>&1 to the command:
* * * * * /var/www/dir/sh/mysql_dump.sh 2>&1 | mail -s "mysql_dump" example#mail.example
From a crond perspective more accurate is to place in to your cron:
MAILTO=example#mail.com
* * * * * /var/www/dir/sh/mysql_dumb.sh
* * * * * /var/www/dir/sh/other.sh
* * * * * /var/www/dir/sh/other2.sh
Look at the last line of mysql_dumb.sh:
/usr/bin/mysqldump -u USER -pPASS DATABASE > /var/www/dir/backup/backup_DB_`date +%d_%m_%Y`.sql
The > is redirecting the output of mysqldump to the file /var/www/dir/backup/backup_DB_date +%d_%m_%Y.sql
Do you want to store a backup of the database locally?
If not, take out the the > /var/www/dir/backup/backup_DB_`date +%d_%m_%Y`.sql and put the crontab entry back to
* * * * * /var/www/dir/sh/mysql_dump.sh 2>&1 | mail -s "mysql_dump" example#mail.example
If you do want a copy of the file locally, I would suggest using tee which will write the output to the file and put the output back out on stdout, which will later be picked up by crontab.
I would change the last line of mysql_dumb.sh to be:
/usr/bin/mysqldump -u USER -pPASS DATABASE | tee /var/www/dir/backup/backup_DB_`date +%d_%m_%Y`.sql
Again I would change the crontab entry back to:
/usr/bin/mysqldump -u USER -pPASS DATABASE > /var/www/dir/backup/backup_DB_`date +%d_%m_%Y`.sql
The advantage here is mail can read the information from stdout and isn't dependent on the file being written and then read correctly. While that may be a small difference, in my experience using tee will be more reliable.
If you want to store your cron job's output on the file on server and also want to send that output file to your mail address then you can use below command.
And you can use it on cronjob to automatically run on specific interval of time, here i am dumping mysql db and sending it to my mail with attachment of dumped sql file.
* * * * * mysqldump --user username --password='p#ssword' DBNAME | gzip > /home/user/db_backup/db_backup_`date +\%d-\%m-\%Y-\%H-\%M`.sql.gz && mailx -a /home/user/db_backup/db_backup_`date +\%d-\%m-\%Y-\%H-\%M`.sql.gz -s 'database backup date:'`date +\%d-\%m-\%Y-\%H:\%M` example#gmail.com
Is there a way to enable and disable Crontab tasks using Bash/Shell?
So when the user starts Server 1, it will enable the Server 1 Crontab line and so on.
And when the user stops Server 1, the Server 1 Crontab line get disabled (#).
Is this possible and how?
Thanks in advance
*/1 * * * * Server 1 check
*/1 * * * * Server 2 check
*/1 * * * * Server 3 check
SERVERNUM=$1
To enable:
crontab -l | sed "/^#.*Server $SERVERNUM check/s/^#//" | crontab -
To disable:
crontab -l | sed "/^[^#].*Server $SERVERNUM check/s/^/#/" | crontab -
Transcript:
barmar#dev$ crontab -l
*/1 * * * * Server 1 check
*/1 * * * * Server 2 check
*/1 * * * * Server 3 check
barmar#dev$ crontab -l | sed '/^[^#].*Server 1 check/s/^/#/' | crontab -
barmar#dev$ crontab -l
#*/1 * * * * Server 1 check
*/1 * * * * Server 2 check
*/1 * * * * Server 3 check
barmar#dev$ crontab -l | sed '/^#.*Server 1 check/s/^#//' | crontab -
barmar#dev$ crontab -l
*/1 * * * * Server 1 check
*/1 * * * * Server 2 check
*/1 * * * * Server 3 check
I suggest you add your cron jobs to /etc/cron.d for every server one script. Then let the cron script scan for some marker file if the cron job should be executed.
As a quick and dirty fix, you can enable or disable the execute permission of the appropriate cron script.
E.g. if you like to prevent locate from automatically updating its database (which can be I/O consuming):
cd /etc/cron.daily
sudo chmod a-x locate
This may be against the cron framework, but it is quickly applied and it works in case of immediate needs.
this is a variant, I use a cronjob that loads it self every night. I just edit a file and it gets reloaded at 10pm everynight. You could make the reload happen more often. I keep a directory of files for each of nodes. The trick is make sure that nobody comments out the reload line.
0 22 * * * crontab /home/ME/cron_files/NODE