rsync is a powerful tool developed by Andrew Tridgell and Paul Mackerras primarily for Unix-based systems, that you can use to backup your entire disk. It is an open-source utility providing fast incremental file transfer by efficiently copying the differences between two sets of files (Computer Hope).
Here is step-by-step guide on how to use rsync to backup an entire disk:
1. INSTALLATION:
If rsync is not installed, first you will need to do this. For Debian based Linux distributions, you can use apt by typing ‘sudo apt install rsync’ in the terminal. For Red Hat based distributions, you can use yum by typing ‘sudo yum install rsync’.
1. BACKUP THE DISK:
The general form of the command you would use is:
`rsync -av —delete “/source/directory/” “/destination/directory/”`
Here, “-a” means archive mode, which ensures preservation of symbolic links, file permissions, user & group ownerships and timestamps, “-v” is for verbose, printing the details to your screen and “—delete” ensures that if you delete a file in your source directory, it will be deleted in your backup as well.
For disk backup, you can replace the source directory with “/”. For instance, if you had an external backup disk mounted at “/mnt/backup\_disk”, you would do:
`rsync -av —delete “/” “/mnt/backup_disk/”`
1. SCHEDULE THE BACKUP:
You can automate the backup by using Cron, a time-based job scheduler in Unix-like systems. You could edit your crontab (Cron table) with ‘crontab -e’ and add the following line to run the backup at 3:00am every day:
`0 3 * * * rsync -av —delete “/” “/mnt/backup_disk/”`
Here “0 3 _ _ ” represents minute, hour, day of month, month and day of week respectively. “” means any.
1. BACKUP TO REMOTE SERVER:
To backup to a remote server instead of a local disk, you can use this syntax:
`rsync -av —delete -e ssh “/source/directory/” “user@remote:/destination/directory/”`
Here, “user@remote” are your username and the remote server’s address. “-e ssh” specifies that rsync should use secure shell (SSH) protocol for data transfer.
Be sure to test your setup to confirm that it is working as expected. Start with a small set of data and check that it is appropriately copied and updated.
Rsync is a command line program, so you need to be comfortable working in a terminal environment to use it. It also has several other options for customization, so you can read the man page (‘man rsync’) for more information.
References:
- [Rsync (Remote Sync): 10 Practical Examples of Rsync Command in Linux](https://www.tecmint.com/rsync-local-remote-file-synchronization-commands/)
- [Introduction to rsync](https://www.lifewire.com/uses-of-command-rsync-2201085)
- [Rsync Manual](https://linux.die.net/man/1/rsync)
- [Rsync](https://www.computerhope.com/unix/rsync.htm)
- [Overview of Cron](https://www.nixtutor.com/linux/understanding-the-cron-schedule-format/)
