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Change Log File Allocation size 1

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mholbert

IS-IT--Management
Jan 10, 2006
105
US
On a sql 2k server, I changed the db backup job on a database, and erroneously forgot to truncate the log file on backup. The log grew to 180GB, instead of the 12 or so GB it would normally be. I shrunk the log back down to its original size, but I cannot find a way to change the amount of space allocated for the log.

Anybody know how to accomplish this?

Any help is appreciated.

MH
 
Use the shrinkfile command.

DBCC SHRINKFILE(<file_name>, TRUNCATEONLY)

If that doesn't work. This next script will. Sometimes you have to run it more than once.


SET NOCOUNT ON
DECLARE @LogicalFileName sysname,
@MaxMinutes INT,
@NewSize INT

-- *** MAKE SURE TO CHANGE THE NEXT 3 LINES WITH YOUR CRITERIA. ***
--USE -- This is the name of the database for which the log will be shrunk.
SELECT @LogicalFileName = ' ', -- Use sp_helpfile to identify the logical file name that you want to shrink.
@MaxMinutes = 2, -- Limit on time allowed to wrap log.
@NewSize = 10 -- in MB

-- Setup / initialize
DECLARE @OriginalSize int
SELECT @OriginalSize = size -- in 8K pages
FROM sysfiles
WHERE name = @LogicalFileName
SELECT 'Original Size of ' + db_name() + ' LOG is ' +
CONVERT(VARCHAR(30),@OriginalSize) + ' 8K pages or ' +
CONVERT(VARCHAR(30),(@OriginalSize*8/1024)) + 'MB'
FROM sysfiles
WHERE name = @LogicalFileName
CREATE TABLE DummyTrans
(DummyColumn char (8000) not null)


-- Wrap log and truncate it.
DECLARE @Counter INT,
@StartTime DATETIME,
@TruncLog VARCHAR(255)
SELECT @StartTime = GETDATE(),
@TruncLog = 'BACKUP LOG ' + db_name() + ' WITH TRUNCATE_ONLY'
-- Try an initial shrink.
DBCC SHRINKFILE (@LogicalFileName, @NewSize)
EXEC (@TruncLog)
-- Wrap the log if necessary.
WHILE @MaxMinutes > DATEDIFF (mi, @StartTime, GETDATE()) -- time has not expired
AND @OriginalSize = (SELECT size FROM sysfiles WHERE name = @LogicalFileName) -- the log has not shrunk
AND (@OriginalSize * 8 /1024) > @NewSize -- The value passed in for new size is smaller than the current size.
BEGIN -- Outer loop.
SELECT @Counter = 0
WHILE ((@Counter < @OriginalSize / 16) AND (@Counter < 50000))
BEGIN -- update
INSERT DummyTrans VALUES ('Fill Log') -- Because it is a char field it inserts 8000 bytes.
DELETE DummyTrans
SELECT @Counter = @Counter + 1
END -- update
EXEC (@TruncLog) -- See if a trunc of the log shrinks it.
END -- outer loop
SELECT 'Final Size of ' + db_name() + ' LOG is ' +
CONVERT(VARCHAR(30),size) + ' 8K pages or ' +
CONVERT(VARCHAR(30),(size*8/1024)) + 'MB'
FROM sysfiles
WHERE name = @LogicalFileName
DROP TABLE DummyTrans
PRINT '*** Perform a full database backup ***'
SET NOCOUNT OFF
 
The first one worked perfectly. Thanks, MH
 
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