Managing weekly backups

Question

I have written a script which takes MySQL dumps and uploads it to Amazon S3. I have added the script to the cronjob and it runs at 2 o'clock in the midnight and uploads the MySQL dump to S3. I am using the date and time stamp as the file name before uploading it to S3.

My problem is I need to manage backups of 7 days on S3 and automatically I have to delete the 8th day backup file from S3 since I am using the date and time stamp as file name to make each file unique, I am not able to figure out how to do it.

And also I have to restore the latest backup in another EC2 instance.

Answer 1

date can help you in figuring out the right 7 day old filename:

$ date -I
2011-12-03
0 thorsten@moppel:~
$ date -I -d '7 days ago'
2011-11-26

Answer 2

Use the following script to rotate the backups after N number of days:

#!/bin/bash
if [ "$#" == "0" ];then
  echo "$0 upper-limit path {command}"
  exit 1
fi
### SSH Server setup ###
SSH_USER="vivek"
SSH_SERVER="nas.nixcraft.in"
START=7
DIR_FORMAT="%d-%m-%Y" # DD-MM-YYYY format
#DIR_FORMAT="%m-%d-%Y" #MM-DD-YYYY format
## do not edit below ##
LIMIT=$( expr $START + $1 )
## default CMD ##
CMD="ls"
SSH_PATH="."
[ "$3" != "" ] && CMD="$3" || :
[ "$2" != "" ] && SSH_PATH="$2" || :
DAYS=$(for d in $(seq $START $LIMIT);do date --date="$d days ago" +"${DIR_FORMAT}"; done)
for d in $DAYS
do
  ssh ${SSH_USER}@${SSH_SERVER} ${CMD} ${SSH_PATH}/$d
done

This script needs some modification, i took it from here.

http://www.cyberciti.biz/tips/ssh-rotate-backup-shell-script.html

You can read the complete article to understand it and modify it according to your needs.

Besides all of it, i would recommend you to use Rsnaphot or Bacula backup for automated backup and recovery.

Answer 3

If you only need 7 days of backups you could use the "weekday name" (%A or %a) or the "day of week" number (%w) with date and let the S3 upload replace last week's file.

FILENAME=$(date '+%A.sql')
mysqldump > $FILENAME