I’m looking for a tool to make snapshots of the system with an ext4 system disk.
It’s worth the time to change to BTRFS. grub-btrfs is a life saver.
dd is the tool you can use. But for a system disk you probably want to run it from a LiveOS
LVM?
Yes it’s on LVM but the system disk is ext4
but the file system is ext4, will it still work?
Assuming this is an option for you, convert your ext4 partition to btrfs (can be done without data loss) and enjoy having proper snapshot support. Timeshift makes it really easy to automate and manage btrfs snapshots.
DD or CloneZilla. Both from live sessions.
Isn’t disk cloning quite different from snapshot? I’m asking for learning purposes. I’ve used Clonezilla for a decade now and it has developed into a superior beast. None of the commercial products can beat it.
It is, but ext4 has no snapshot capability as far as I know.
back in time? it uses rsync