In working with SQL 2005 Maintenance Plan backup cleanup tasks, a frustrating bug was found. It seems that when the ability to select “hours” as a time criterion was added in SP2, the door was opened for misinterpretation of time units. For example, you can, in your local Management Studio, set the Plan to delete files greater that 4 days old, and when run on the server the Plan will delete files only greater than 4 WEEKS old. This was the full mapping I found:
SET ACTUAL
Hours -> Days
Days -> Weeks
Weeks -> Months
Months -> Years
Years -> Years
I don’t know yet if this is fixed in 2008. For 2005 at least, I suggest refraining from using the built-in “Maintenance Cleanup Tasks” in Maintenance Plans, and instead use a T-SQL Statement task with the snippet below. This will truly delete greater than 4 days. Set your time criteria however you like.
DECLARE @DateOlderThan datetime
SET @DateOlderThan = DATEADD(day,-4,GETDATE())EXEC master.dbo.xp_delete_file
0 -- delete files
,N'H:\SQLBackup\INST3' --full path to the main directory
,N'bak'-- file extension
,@DateOlderThan-- delete files created before this timestamp
,1-- Including first-level sub
Jeff, I think you’ll find some handy procedures in the admin database to handle these issues. Our maintenance procedures and the backup procedures will handle these issues for you. I have never been a fan of maintenance plans as they are very limited and in the end, only cause more frustration than they’re worth.
We just use them for things like rolling backups on DEV and QA servers. For that, they do everything we need.