From 8e612c0af97a7b9f30784436ef12ca00cc25b3cc Mon Sep 17 00:00:00 2001 From: Nathan Steel Date: Fri, 26 Aug 2022 12:12:05 +0100 Subject: [PATCH] Add backup-with-cron blog article --- blog/backup-with-cron.html | 113 ++++++++++++++++++++++++++++++ blog/guide-to-server-hosting.html | 2 +- blog/index.html | 1 + 3 files changed, 115 insertions(+), 1 deletion(-) create mode 100644 blog/backup-with-cron.html diff --git a/blog/backup-with-cron.html b/blog/backup-with-cron.html new file mode 100644 index 0000000..5c06530 --- /dev/null +++ b/blog/backup-with-cron.html @@ -0,0 +1,113 @@ + + + + + + + + + + + + + Automating Backups with Cronjobs + + + +
+

Automating Backups with Cronjobs

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Backups are wonderful things that save hours upon hours of work, and stress, so long as they're actually made in the first place!

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Automatically taking backups allows for peace of mind that your work won't be lost forever whilst you go about your normal workflow..

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Create a backup script

+

You can just call rsync, etc. in cron, but I recommend making a backup script (or a few) for each specific type of backup you want to make.

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Create the file where-ever you want to keep them, for the sake of this, it'll be a scripts directory in your home directory

+ 
vim ~/scripts/backup_script.sh
+

And add whatever your backup scripts wants to do. If you've no idea, check out my rsync, and rdiff articles first.

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rdiff-backup $DIRECTORY_TO_BACKUP $DIRECTORY_TO_BACKUP_TO
+rdiff-backup --force --remove-older-than 2W $DIRECTORY_TO_BACKUP_TO
+

The above example will backup a directory, and remove any changes from 2 weeks ago.

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Now make the script executable

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chmod +x ~/scripts/backup_script.sh
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Add a cronjob

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Now for the automation part. Using cron we can set this script to run at many time variations. I recommend crontab guru to learn more about the expressions used for cron.

+

Edit the cron table (crontab)

+ 
crontab -e
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And add the following

+ 
* */2 * * * /home/$USERNAME/scripts/backup_script.sh
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This will run the backup script every 2 hours, every day

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An advanced backup script

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An advantage of using a script for backups, is that it allows for more intricate functionality, you may not need to use this functionality, but it's greatly useful.

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The script below is something I wrote to backup my home directories for each of my servers. It's used to make hourly backups, and send these backups to a remote server daily at midnight.

+
#!/bin/bash
+
+# Set locations to backup/backup to from the flags
+while getopts s:d:b:r:R:n: flag
+do
+        case "${flag}" in
+            d) DATA=${OPTARG};;
+            b) BACKUPDIR=${OPTARG};;
+            r) REMOTE=${OPTARG};;
+            R) REMOTEBACKUP=${OPTARG};;
+            n) NOW=${OPTARG};;
+        esac
+done
+
+# If the backup directory doesn't exist, make it
+mkdir -p $BACKUPDIR
+
+# Incremental backup of the directory locally
+rdiff-backup $DATA $BACKUPDIR
+# Don't keep changes from over 1W ago
+rdiff-backup --force --remove-older-than 1W $BACKUPDIR
+
+# Backup to remote
+# Get the hour/minute time
+TIME=$(date +%H%M)
+
+# If it's a midnight backup, or a manual backup with -n 1 flag set
+if [ "$TIME" = 0000 ] || [ "$NOW" = 1 ]
+then
+        # Create the remote directory for backup if it doesn't exist
+        ssh $REMOTE mkdir -p $REMOTEBACKUP
+
+        # Copy the backup to the remote location
+	# -e ssh makes it secure
+        rsync -azh -e ssh \
+                --delete \
+                $BACKUPDIR \
+                $REMOTE:$REMOTEBACKUP
+fi
+
+

Which is called in the crontab like so

+
# Hourly rdiff-backup of $DIRECTORY_TO_BACKUP
+0 */1 * * * $SCRIPT_LOCATION -d $DIRECTORY_TO_BACKUP -b $LOCATION_TO_SAVE_BACKUP -r $EXTERNAL_SERVER_SSH -R $EXTERNAL_SERVER_BACKUP_LOCATION
+ +

This script can easily be used for many different directories, on each server without needing to change the script itself. All that's needed is to change the cronjob, and/or add another cronjob changing the values it takes.

+ +
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+ + + + + diff --git a/blog/guide-to-server-hosting.html b/blog/guide-to-server-hosting.html index 0ccc298..522f076 100644 --- a/blog/guide-to-server-hosting.html +++ b/blog/guide-to-server-hosting.html @@ -69,7 +69,7 @@ diff --git a/blog/index.html b/blog/index.html index 303100c..042969d 100644 --- a/blog/index.html +++ b/blog/index.html @@ -38,6 +38,7 @@

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