How to do system backup

[TheFu]

@TheFu:
The original question was simple and from a "newbie".
You are scaring people away here!
We all appreciate your knowledge on this, but really... you can take things too far. Just a friendly hint.

Newbies aren't dumb people. They can decide for themselves what is good advice. 2 commands are hardly "scary" - or can easily be ignored. We are all different. Someone who wants to "dig into the OS", will probably appreciate the different options.

Just a friendly hint.

[tomislav.stasina]

Thank you all for all this useful information.

I appreciate both basic and advanced replies - although I will start with more basic solutions and go advanced if I feel I need more.
@TheFu - thanks for detailed reply, I will probably read it multiple times. Maybe it's not all clear now, but it's good to have information somewhere in head to recall later when I get more comfortable with system.

[mastablasta]

since we are talking about local backup and not separate disk image or external (server) backup and option would be to use BTRFS or ZFS4linux. unfortunately that choice should be made at the system install. but i am just commenting here in case someone else reads this. These file systems can make snapshots of current install on local drive which can later be restored. they dont' guard against disk failure, but they do guard slightly better against user tinkering.

beside the ones already mentioned in this thread (which are all very good options) there are a few more with GUI interface i tried and found useful:

1. incremental & full backup (push method to internal, external drive or server)

• Areca
• Duplicati

2. incremental & full backup (pull method to internal, external drive or server)

• UrBackup

3. full disk image backup

• Rescuezilla
• Clonezilla

[rsteinmetz70112]

For a beginner I'd stay with the backup system provided by the distro. Currently for Ubuntu 20.04 I believe it's Deja Dup. There are a gazillion backup solutions for Linux including the many options listed above and many home brew options, which is what I do. I believe it's more important to start the backups early than to search for the perfect system. You can always change it later if you decide you want to.

Here is an article on how to set it up. https://www.lifewire.com/backup-ubuntu-4126286

[TheFu]

Don't forget Back-In-Time https://backintime.readthedocs.io/en/latest/ . Used that tool for Mom's system years ago. It was much better than Duplicati at the time. Back-In-Time uses rsync+hardlinks, which is what many of the other tools use to support versioned backups. For about a decade I used rsnapshot which was a script published in an O'Reilly UNIX book that also does rsync+hardlinks. rsnapshot is in the Ubuntu repos. https://ubuntu.com/server/docs/tools-rsnapshot There are other variations on rsnapshot, like rbackup.

For Ubuntu Desktop users, https://help.ubuntu.com/stable/ubunt...up-why.html.en

Tested Duplicati and in 8 hrs, it hadn't backed up 100G. Duplicati, DejaDup, duplicity are all in the same family. These tools have all the features for great backups, but the implementation, performance has never impressed me. They work in the very old way, like we did backups in 1970. Duplicati can't still be that slow.

Newer tools like rdiff-backup work in exactly the opposite way. It is a comparison between SCCS and RCS version control systems (that probably doesn't help anyone but the old programmers). Duplicity gets a full backup, then creates diffs off it. The restore process has to being with that full backup, then all the diffs since it happened to restore a system. rdiff-backup maintains the full backup and creates diffs between B-0 and B-1. 80+% of the time, when we need to restore, it is the last backup that is needed, so that is just a cp to restore. Duplicity needs a new "full" created weekly or monthly to avoid too many differences and possible corruption. With rdiff-backup we prune away the oldest diffs as each new backup is created, once we have the number of versions we want. If any intermediate version is removed, all the later versions are considered corrupted. The same applies to all efficient, versioned, backups using forward or reverse diffs.

BTW, I've used fsarchiver to create backup images for raspberry pi systems. Good tool, for what it does. Just don't expect versioning or great storage efficiency from any imaging tool.

[GhX6GZMB]

@TheFu:
Based on previous posts by you, I now also use Back in Time now for backing up /home.

I use two backup programs: Timeshift for system backup and Back in Time for /home backup.

This has something to do with my way of working, and my environment, I use laptops that are laid out for several users (not simultaneously, of course), where my account is the admin/sudo user, others are guests.

When I do a system backup, it's normally because I'm experimenting with something on the OS that won't touch the /home files. So no reason to back them up (/ and /home are always on separate partitions).
For this I use Timeshift, because it's optimized (at least in the GUI version) for system backup, is sudo protected and very fast after initial backup.

For /home backups I use Back In Time, because it's NOT sudo protected, and every user has resposibility for his/her own workfiles (this includes myself), and because it's originally designed/optimzed for /home backups.

Needless to say, I do this using the GUI versions.

I understand your preference for CLI use, but I try to approach maximum productivity by balancing CLI and GUI according to the task.

[TheFu]

Back-in-Time can do full system backups under root's crontab these days. Think there's a GUI toggle switch. It has some cool ideas, like having hourly backups for the most recent 2 days, then it selectively removes backups as they get older and older. This happens by default. I never learned how to create a custom schedule for how to keep what I really wanted, but I assume it is possible.
I'd like hourly for 2 days, daily for 2 weeks, then weekly for 4-8 weeks, then monthly for up to 12 months. Don't know that I'm interested in retaining a yearly backup or 5. Alas, Back-in-Time has the same flaw that all rsync+hardlink backup solutions have - they don't maintain the ownership, group, and permission changes over time. It isn't a problem too often - until it is - then we are screwed.

I can see where Timeshift's integration with brtfs would make it an excellent choice for that file system.