Race condition on incremental backups I am planing to automate to take incremental backups on a range of sql servers from 2000 to 2012, on a variety of windows too.  This will be done with a vbs script that runs on task scheduler.  I want to know if there is a problem to occasionally start a new incremental backup when the previous one is still running or I must be sure that there is a lapse of time doing nothing.  The rest of details are covered, I keep all the files, and I test (restoring on other server) all the backups.
I want to know if there is a problem to occasionally start a new incremental backup when the previous one is still running


For SQL Server 2000

You would not be allowed to start new differential backup unless the previous one finishes.

For SQL Server 2005 and above

You can start new differential backup while old one is still running but new one would be blocked by already running differential backup. The new diff backup will only start after old one has finished.

This Blogs.msdn article and this SE thread would help you in understanding similar behavior