Full backup at 1am, not started by my maintenace plan I set up a complete set of Maintenance Plan. 


Full backup of all databases at 3AM.
Differential backup at 6h30, 12h30, 18h30 and 00h30.
Log backup at each hour, at 45 minutes (1h45, 2h45...)


In my SQL history list, (I use this script to find it: http://luvit.me/1GAfpPG ) I see a full backup a 1AM, with a GUID as the "physical_device_name" and a NULL value at as the "backupset.name".

WHO start the backup? How can I found if another guy use another tool for backup? Did this backup is started by SQL Server himself?

The problems is currently, we have some tools that do a database conversion for a new and not yet ready ERP, and the conversion tool change the Recovery mode: if the recovery mode is changed while this weird backup is running, the conversion tool crash... 

Sorry if it's a noob question, but I didn't find anything ... 

Thank you
Add columns:
    msdb.dbo.backupset.software_vendor_id, 
    msdb.dbo.backupset.user_name

to your query.

If your software vendor id = 4608 then its sql native, anything else is a third party software. The user name should give you some clues as to what is occurring.

Also check SQL Agent for jobs executing at around that time.