Where dump saved by default?

Hello. I could not find an answer in the search. I damaged the root partition. In the "fstab" it is written that the dump makes copies. Where to find them? Thank you in advance.
Why has the system dump setting in fstab if it is not working and need to configure manually?

From the fstab(5) manual page:
The fifth field, (fs_freq), is used for these file systems by the dump(8)
    command to determine which file systems need to be dumped.  If the fifth
     field is not present, a value of zero is returned and dump will assume
     that the file system does not need to be dumped.  If the fifth field is
     greater than 0, then it specifies the number of days between dumps for
     this file system.

This information is used by dump -W (or dump -w)) with /etc/dumpdates to determine if a filesystem needs to be dumped, from dump(8):

-W      Tell the operator what file systems need to be dumped.  This
            information is gleaned from the files dumpdates and /etc/fstab.
             The -W option causes dump to print out, for each file system in
             the dumpdates file the most recent dump date and level, and
             highlights those file systems that should be dumped.  If the -W
             option is set, all other options are ignored, and dump exits

     -w      Is like -W, but prints only those file systems which need to be

So in summary, dump(8) is never run automatically and the fstab(5) entries are only used if dump(8) is run with certain options.