Originally Posted by JeremyBoden
rsync can't do a backup of a running system because some of the files are locked.
Exactly which files are locked? This is not Windows. Not a single file is locked but database files like Postgresql or MySQL can be inconsistent when backed up on file level.
Originally Posted by Almaz
I guess I wasn't clear. I'd like to do a complete restore of the computer remotely over ssh. Is it possible in linux? For example in windows Acronis True Image allows to do a complete restore on it's own machine even remotely. Can rsync to do a live restore of the whole system?
Yes it can. Contrary to Windows there a no magic files being locked or inaccessible. In Windows you need special agents to perform read or write and even then it can fail.
The only risk is what I said inconsistent database files. You'd need to make a database dump before backup and copy that dump file. During restore both database files and dump are restored. In case the database was corrupted you can restore it from the dump.
Now keep in mind that rsync works on the file level
. If you damage your installation on the file level
this can be restored. If you damage something more significant like your MBR or partition tables, you can't expect rsync to repair that.