Windows offers Diskpart utility to extend the volume or partition. In situations where a volume or partition on which the database files reside need to be extended, it is recommended that the SQL Server services be first stopped before extending the volume to create more space. However; it may not be possible to incur downtime by stopping SQL Server services. In these cases, you can still use diskpart utility to extend the disk volumes when SQL Server services are online.
Once the disk volumes are extended successfully, it is also recommended but not required to run database consistency check using the DBCC CHECKDB command to ensure the logical and physical integrity of all the objects in the specified database. DBCC CHECKDB can take significantly longer time depending on the size of the database. In such cases, you can consider running dbcc checkdb with physical_only option to limit the checking to the integrity of the physical structure of the page and record header and the allocation consistency of the database. You can also consider using the trace flags 2562 and 2549 as described in the knowledge base article 2634571 to improve the performance of DBCC CHECKDB command when used with PHYSICAL_ONLY option.
DBCC Checks and Terabyte-Scale Databases
Article ID: 2732669 - Last Review: 28 Jul 2012 - Revision: 1