Check how much space used by Data file in Sql Server

select
 a.FILEID,
NAME = left(a.NAME,15),
 [FILE_SIZE_MB] =
  convert(decimal(12,2),round(a.size/128.000,2)),
 [SPACE_USED_MB] =
  convert(decimal(12,2),round(fileproperty(a.name,'SpaceUsed')/128.000,2)),
 [FREE_SPACE_MB] =
  convert(decimal(12,2),round((a.size-fileproperty(a.name,'SpaceUsed'))/128.000,2)) ,
  FILENAME = left(a.FILENAME,30)
from
 dbo.sysfiles a;

Check when last time server re-start

SELECT
[ms_ticks] AS ms_since_restart,
[ms_ticks]/1000 AS seconds_since_restart,
CAST([ms_ticks]/1000/60.0 AS DECIMAL(15,2)) AS minutes_since_restart,
CAST([ms_ticks]/1000/60/60.0 AS DECIMAL(15,2)) AS hours_since_restart,
CAST([ms_ticks]/1000/60/60/24.0 AS DECIMAL(15,2)) AS days_since_restart,
DATEADD(s,((-1)*([ms_ticks]/1000)),GETDATE()) AS time_of_last_restart
FROM sys.[dm_os_sys_info];
=========================================================================
SELECT
DATEADD(s,((-1)*(DOSI.[ms_ticks]/1000)),GETDATE()) AS last_SERVER_restart,
D.create_date,
(DATEDIFF(s, DATEADD(s,((-1)*(DOSI.[ms_ticks]/1000)),GETDATE()), D.create_date)) AS recovery_time_seconds
FROM sys.[dm_os_sys_info] DOSI
CROSS JOIN sys.[databases] D
WHERE D.[name] = 'tempdb';