If you are on probation for a DUI, sometimes the judge will require you to served jail time as a condition of probation.  You will remain on probation until such time as you violate your probation.  If you never violate, you will be discharged.  If you do violate a condition, then at that time a warrant could be issued for your arrest and you again be arrested.If you were on proabation for a DUI, and while on probation got arrested for a new and different case, then it is possible that you could be released on the new charge.... and then rearrested later for a probation violation once the court learned about the new charge.  It's all about the timing of when your probation officer or the court learn about the charge.