File Permission of Backup

Hello,

I have a problem with the files which are created by the XtraBackup.

In the Production I have a cronjob which execute a fullbackup every day. The cronjob is execute as root.
The files will be saved on a NAS, but the files can’t access because there are no rights defined.

Is it possible to set the permissions of the files in the command?

Thanks for your Help.
Christoph