What does Msdb do in SQL Server?

Question

The msdb database is a system database that is used by several SQL Server components such as the SQL Server Agent service. In addition to SQL Server Agent configuration and task information, replication, log shipping, and maintenance plan data are stored in the msdb database.

What is the function of Msdb in SQL Server?

The msdb database is used by SQL Server Agent for scheduling alerts and jobs and by other features such as SQL Server Management Studio, Service Broker and Database Mail. For example, SQL Server automatically maintains a complete online backup-and-restore history within tables in msdb.

What happens when Msdb DB is down?

If Msdb is down, then your sql server agent wont start, hence the jobs will not even run in the first place.

Why is MSDB database so large?

MSDB stores backup and restore history. Imagine a server with 2000 databases that takes a log backup of all of them every 15 minutes. That's 192,000 new rows into the backupset and backupmediaset tables EVERY DAY! Keeping a few weeks or months of history can cause the size of MSDB to get very large.

Do I need to backup Msdb?

Yes, yes, yes! In the event that the MSDB database becomes corrupt or if the server crashes and the MSDB database needs to be recovered, a backup will be the only way to do so. This database also houses data that could be accidentally damaged by an administrative user.

Expert · Answer