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mysqllinuxshellcron

Linux shell script for database backup

I tried many scripts for database backup but I couldn't make it. I want to backup my database every hour.
I added files to "/etc/cron.hourly/" folder, changed its chmod to 755, but it didn't run. At least I write my pseudo code.

I would be happy if you can write a script for this operation and tell me what should I do more ? After adding this script file to /etc/cron.hourly/ folder.

  • Get current date and create a variable, date=date(d_m_y_H_M_S)
  • Create a variable for the file name, filename="$date".gz
  • Get the dump of my database like this mysqldump --user=my_user --password=my_pass --default-character-set=utf8 my_database | gzip > "/var/www/vhosts/system/example.com/httpdocs/backups/$("filename")
  • Delete all files in the folder /var/www/vhosts/system/example.com/httpdocs/backups/ that are older than 8 days
  • To the file "/var/www/vhosts/system/example.com/httpdocs/backup_log.txt", this text will be written: Backup is created at $("date")
  • Change the file owners (chown) from root to "my_user". Because I want to open the backup and log files from the "my_user" FTP account.
  • I don't want an email after each cron. >/dev/null 2>&1 will be added.
Solution

  • After hours and hours work, I created a solution like the below. I copy paste for other people that can benefit.

    First create a script file and give this file executable permission.

    # cd /etc/cron.daily/
# touch /etc/cron.daily/dbbackup-daily.sh
# chmod 755 /etc/cron.daily/dbbackup-daily.sh
# vi /etc/cron.daily/dbbackup-daily.sh

    Then copy following lines into file with Shift+Ins

    #!/bin/sh
now="$(date +'%d_%m_%Y_%H_%M_%S')"
filename="db_backup_$now".gz
backupfolder="/var/www/vhosts/example.com/httpdocs/backups"
fullpathbackupfile="$backupfolder/$filename"
logfile="$backupfolder/"backup_log_"$(date +'%Y_%m')".txt
echo "mysqldump started at $(date +'%d-%m-%Y %H:%M:%S')" >> "$logfile"
mysqldump --user=mydbuser --password=mypass --default-character-set=utf8 mydatabase | gzip > "$fullpathbackupfile"
echo "mysqldump finished at $(date +'%d-%m-%Y %H:%M:%S')" >> "$logfile"
chown myuser "$fullpathbackupfile"
chown myuser "$logfile"
echo "file permission changed" >> "$logfile"
find "$backupfolder" -name db_backup_* -mtime +8 -exec rm {} \;
echo "old files deleted" >> "$logfile"
echo "operation finished at $(date +'%d-%m-%Y %H:%M:%S')" >> "$logfile"
echo "*****************" >> "$logfile"
exit 0

    Edit:
    If you use InnoDB and backup takes too much time, you can add "single-transaction" argument to prevent locking. So mysqldump line will be like this:

    mysqldump --user=mydbuser --password=mypass --default-character-set=utf8
          --single-transaction mydatabase | gzip > "$fullpathbackupfile"