Hi all. I'm seeing an issue with my Backup directory. Currently I have maintenance running on all of my databases to run complete backups daily for the databases and transaction logs. They are set to go to "D:\Program Files\Microsoft SQL Server\MSSQL\BACKUP" with a ".BAK" extension. I also have it set to remove files older than 5 days.

I noticed the directory was growing to over 100GB's. I went to the backup directory and noticed I had 700+ files with a .TRN extension. These are totally to over 85GB's. The remainder files are 5 days worth of backups.

My question is what exactly are the .TRN files (I'm an SQL noob). I would like to free up some space on this server, but I don't want to just go and delete stuff. Please advise. Thank you.