The data file (mdf) that wouldn't grow

Recently we had an issue where a database was unable to grow the mdf file. This was causing availability issues as no new inserts were able to be accepted. The usual suspects were checked - file autogrowth and maximum file sizes, but no problems were found there. The mdf file was stuck at 47GB. Trying to increase it manually failed. The easiest fix was to create a secondary data file to allow new data (.ndf) to be added. This allowed the business to continue. The regular DBCC checkdb on the database was failing as the database snapshot could not be created. It appeared that the issue was not a database issue but a problem with the underlying SAN. The SAN administrator during a maintenance window made some changes that resolved the issue. No problem with file growth or running DBCC's. Morale to the story - its' not always the database that is the root cause. The SAN administrator never actually stated what changes were made.