how to create unlimit size my own log file?

Hello ,
I want to save some data on a file once every 5 min
how can I make it ? and save all the data in 1 file ?

Thanks,

I suggest using external logging server. Search google for “Syslog server”. Any tool will do, they are all compatible with RouterOS. In the Syslog server you can then make filters and separate files as you please.

I will look in to it ,
Thanks ,