We recently had a 64 bit server installed with sequel server(running a data warehouse). Our backups fail with .ldf file locked issues. I would like to understand how to determine what files are writing to this log file ( the actual database that should be logging transactions here is unused - so something else is using it I think - it's a demo database ), so what has it locked, and what issues our Data Protector 6.0 backup software may be experiencing. and yes - it is over 400 gigs big. We did try regular windows backup - and that seemed to work till we ran out of disk space on the backup device. I asume once the file is backed up it'll resize itself by deleteing first in records until it reaches it's threshold? We have no SQL expertise in our company - I'm learning on the fly here. Any leads welcome and appreciated. Michael in Calgary