I am running Raspberry PI and I would like to dump full file system without shutting down the system. One machine runs nginx and another runs PostgreSQL. I have had a good success with FreeBSD and dump software, because it is part of the OS and core team maintains it.
However, dump utility is no longer maintained by the original developer and is effectively getting too old. I am no longer sure what is a dump-like solution that's easy to work with at a file system level.
I would like a backup tool that does not bring a million dependencies with MBs of files. Something that works on server without X Windows and can send backup to an externally attached USB drive. Nothing fancy. No network infrastructure. Incremental backups would be greatly appreciated. Ability to pipe to a compression program is a plus, just like I did with dump.
I'd like to be able to apply a similar solution on actual Debian and Ubuntu VMs. When I go to Ubuntu I might have to deal with newer ext file systems. Not sure what is supported there.
If there is no good live backup solution, I am willing to take the system down and back it up using another system. It is not ideal, but it would work.
Any advice would be greatly appreciated.
P.S. All mentioned systems are Debian based and I feel that it is appropriate to ask on Debian user list.