Wow, what great timing to repost this article. A customer of ours ran into this over the weekend. The cause in sys.databases appears to be ACTIVE_BACKUP_OR_RESTORE.
When I look at the maintenance plan history, his backups started taking 20+ hours to run. Beginning on 8/25/2012 we can see very long backup durations. The maintenance plan checks database integrity, deletes old backups, then runs a new backup. On 9/3/2012, the maintenance plan failed on the DBCC CHECKDB step with the following error:
Executing the query "DBCC CHECKDB(N'DPTS') WITH NO_INFOMSGS
" failed with the following error: "The transaction log for database 'DPTS' is full. To find out why space in the log cannot be reused, see the log_reuse_wait_desc column in sys.databases
A database snapshot cannot be created because it failed to start.
The database snapshot for online checks could not be created. Either the reason is given in a previous error or one of the underlying volumes does not support sparse files or alternate streams. Attempting to get exclusive access to run checks offline.
The database could not be exclusively locked to perform the operation.
Check statement aborted. The database could not be checked as a database snapshot could not be created and the database or table could not be locked. See Books Online for details of when this behavior is expected and what workarounds exist. Also see previous errors for more details.
Could not write a checkpoint record in database ID 11 because the log is out of space. Contact the database administrator to truncate the log or allocate more space to the database log files.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.
Not out of space on the physical disk. Recovery model is Simple. Any ideas where I should go next?