Code Example 1:

-- sp_dbspace procedure. Create in the master database

CREATE  procedure sp_dbspace
as

SET QUOTED_IDENTIFIER ON 
SET ANSI_NULLS ON 
SET ANSI_WARNINGS ON

declare @dbname sysname
declare @dbid int
declare @dbsize int
declare @maxid int
declare @sqlstring varchar(1024)
declare @bytesperpage  dec(15,0)
declare @pagesperMB               dec(15,0)

SET @MaxId = (SELECT MAX(dbid) FROM MASTER.dbo.sysdatabases)
SET @dbid = 1 
SET @dbsize = 0
SET @bytesperpage = (select low from master.dbo.spt_values
    where number = 1 and type = 'E')
SET @pagesperMB = (SELECT 1048576 / @bytesperpage)



CREATE TABLE #dbspacetmp   (
            dbname varchar(128), 
            dbpages dec(15,0), 
            dbpagespermb dec(15,0), 
            dbreserved dec(15,0), 
            dbsize dec(15,0)
                                                )
WHILE @dbid <= @MaxId 
BEGIN
/*  We want summary data.
**          Space used calculated in the following way
**          @dbsize = Pages used
**          @bytesperpage = d.low (where d = master.dbo.spt_values) is
**          the # of bytes per page when d.type = 'E' and
**          d.number = 1.
**          Size = @dbsize * d.low / (1048576 (OR 1 MB))
*/

  SET @dbName = (SELECT name FROM MASTER.dbo.sysdatabases WHERE dbid = @dbid)
  IF (@dbName IS NOT NULL) 
    BEGIN
            dbcc updateusage(@dbname) with no_infomsgs
            SET @sqlstring = 'INSERT INTO #dbspacetmp 
                        SELECT '''+ @dbname +'''           AS dbname,
                        (select sum(convert(dec(15),size)) FROM ['+ @dbname +'].dbo.sysfiles) 
                                                                     AS dbpages,
                        (SELECT '+ str(@pagespermb,15,2) +')    		AS dbpagespermb,
                        ((select sum(convert(dec(15),reserved)) 
                        from [' + @dbname + '].dbo.sysindexes where indid in (0, 1, 255))/
                        '+ str(@pagespermb,15,2) + ')                AS dbreserved,
                        (select sum(convert(dec(15),size)) FROM ['+ @dbname +'].dbo.sysfiles)/
                        (SELECT '+ str(@pagespermb,15,2) +')    		AS dbsize'
                        EXEC (@sqlstring)
            SET @dbid = @dbid + 1
    END
     ELSE
        SET @dbid = @dbid + 1
END


INSERT INTO [datacollectorservername].[master].[dbo].[spt_dbspace]

-- NOTE: Substitute your data collector server name above!!!

SELECT            (SELECT @@SERVERNAME) AS servername,
            dbname AS dbname, 
            dbsize AS dbsize, 
            dbreserved AS dbreserved, 
            dbsize-dbreserved AS dbfree,
            getdate() AS snapshotdate
FROM #dbspacetmp

DROP TABLE #dbspacetmp

GO

Code Example 2:

--Create spt_dbspace table in master on data collector server
USE MASTER
GO 

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[spt_dbspace]') 
     and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[spt_dbspace]
GO

CREATE TABLE [dbo].[spt_dbspace] (
            [servername] [varchar] (128) NULL,
            [dbname] [varchar] (128) NULL ,
            [dbsize] [decimal](15, 0) NULL ,
            [dbreserved] [decimal](15, 0) NULL ,
            [dbfree] [decimal](15, 0) NULL ,
            [snapshotdate] [datetime] NULL 
) ON [PRIMARY]
GO

Code Example 3:

-- Create procedure on the data collector server in the master database.
CREATE    procedure sp_dbspaceall 
as

SET QUOTED_IDENTIFIER ON 
SET ANSI_NULLS ON 
SET ANSI_WARNINGS ON

declare @servername sysname
declare @serverid int
declare @maxid int
declare @sqlstring varchar(1024)
 
SET @MaxId = (SELECT MAX(srvid) FROM MASTER.dbo.sysservers)
SET @serverid = 0 


WHILE @serverid <= @MaxId 
BEGIN
/*  We want summary data.
**          Space used calculated in the following way
**          @dbsize = Pages used
**          @bytesperpage = d.low (where d = master.dbo.spt_values) is
**          the # of bytes per page when d.type = 'E' and
**          d.number = 1.
**          Size = @dbsize * d.low / (1048576 (OR 1 MB))
*/

  SET @servername = (SELECT srvname FROM MASTER.dbo.sysservers WHERE srvid = @serverid)
  IF (@servername IS NOT NULL) 
    BEGIN
            SET @sqlstring = '['+ @servername + ']' + '.[master].[dbo].[sp_dbspace]'
            EXEC (@sqlstring)
            SET @serverid = @serverid + 1
    END
     ELSE
        SET @serverid = @serverid + 1
END

GO