iam using mikrotik 3.27 i am running 600 user in userman but i m creating backup after create file size is to much over 70 mb and usermanager is to slow day by day plz anser me any solution reduse file size hai slow problem

Try deleting logs. Perhaps it would be more convenient to delete them in console, by typing It could take time. If you have almost full hard disk, this could cause problems, because when deleting logs, it creates a backup of each log to provide undo option. In that case you could try deleting some logs (let's say 1000), rebooting the router, deleting some more logs (2000), rebooting, deleting 4000, etc.