Tempdb won't shrink

Question

SQL 2008 R2
We’ve been on SQL 2008 R2 for about a year and have had zero tempdb problems. 
SQL does a good job of managing its size, until now. 
Tempdb is configured with 8 data files and 1 log file. 
Each data file is 250 mb and the log is 2 gb, for a total/initial size of 4gb. 
In the last week it’s grown to 11 gb and I can’t shrink it. 
There are zero open trans, and dbcc shrinkfile truncateonly and specifying a size do nothing. 
We bounced the server and tempdb came back at the exact 11 gb size. 
Even after the reboot with nothing going on with the server I can’t shrink it. 
No, we’re not having space issues but obviously something is going on that I’d like to get to the bottom of. 
I’ve read kb 307487 several times so I don’t need a link to it, thanks.
Does anyone have any idea why this just happened, and more importantly what to do? 
Is my only option to start SQL in minimal config mode and address it that way? 
Obviously that’s a tough thing to do with a Prod box.
Thanks in advance,
André
André

Answer 1

Hi,
Just to confirm are you checking the file sizes via ssms, looking at the file system or script?
If possible can you run the following to double check.
USE [tempdb]
GO
EXEC sp_spaceused @updateusage = N'TRUE';
GO
EXEC sp_msforeachtable 'EXEC sp_spaceused ''?'''
GO
SELECT
mf.[file_id] [FileID]
,sf.[name] [LogicalName]
,mf.[type_desc] [FileType]
,FILEPROPERTY(sf.[name],'SpaceUsed')*CONVERT(FLOAT,8) [SpaceUsed_KB]
,(sf.[size]-FILEPROPERTY(sf.[name],'SpaceUsed'))*CONVERT(FLOAT,8) [AvailableSpace_KB]
,sf.[size] * CONVERT(FLOAT,8) [Size_KB]
,LTRIM(CASE mf.[is_percent_growth] WHEN 1 THEN STR(mf.[growth]) +' %' ELSE STR(mf.[growth]*CONVERT(FLOAT,8))+' KB' END) [AutoGrowth]
FROM sys.master_files mf
INNER JOIN sys.database_files sf ON mf.[file_id] = sf.[file_id] AND mf.[database_id] = DB_ID()
GO
Jon