I recent took a backup using mysqlbackup.
While restoring it, I noticed that the files that were copied into datadir are with
root:root (user:group) instead of
Is anything wrong with taking backup or what?....
Since it is a backup, you are right to be concerned with whether it can be restored or not.
To be on the safe side, you must run
immediately after the backup so mysql doesn't barf when restoring it.
Otherwise, you may get an OS error concerning file permission during the restoration or mysql startup