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Merged
BrentOzar merged 3 commits into from
Apr 26, 2026
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for #3959 - added check for backup to NUL device #3960

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for #3959 - added check for backup to NUL device
VladDBA Apr 25, 2026
0233d0f
Apply suggestion from @Copilot
BrentOzar Apr 25, 2026
409bcf4
sp_BlitzBackups: use @StartTime for NUL device check
BrentOzar Apr 26, 2026
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36 changes: 36 additions & 0 deletions sp_BlitzBackups.sql
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Expand Up @@ -1101,6 +1101,42 @@ IF @ProductVersionMajor >= 12
INSERT #Warnings ( CheckId, Priority, DatabaseName, Finding, Warning )
EXEC sys.sp_executesql @StringToExecute;

/*Looking for backups directed at the NUL device.*/
SET @StringToExecute =N'SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;' + @crlf;

SET @StringToExecute += N'SELECT
14 AS CheckId,
100 AS [Priority],
bs.database_name AS [Database Name],
''Backup to NUL device'' AS [Finding],
''The database '' + QUOTENAME(bs.database_name) + '' has had '' + CONVERT(VARCHAR(10), COUNT(*)) + '' backups to the NUL device in the last 30 days, the latest one being on ''+
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@BrentOzar BrentOzar Apr 25, 2026

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Let's remove the 30 day reference and just say "backups to the NUL device, the latest one being on" since we're using the @HoursBack parameter.

CONVERT(NVARCHAR(25),MAX(bs.backup_finish_date),120)+''. These backups do not exist.'' AS [Warning]
FROM ' + QUOTENAME(@MSDBName) + '.dbo.backupset AS bs
INNER JOIN ' + QUOTENAME(@MSDBName) + '.dbo.backupmediafamily bmf ON bs.media_set_id = bmf.media_set_id
WHERE UPPER(bmf.physical_device_name)= N''NUL''
AND (bs.is_copy_only = 1 OR bs.recovery_model = N''SIMPLE'')
AND bs.backup_finish_date >= DATEADD(DAY, -30, SYSDATETIME())
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@BrentOzar BrentOzar Apr 25, 2026

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Instead of hard-coding 30 days back, let's use the @starttime variable, which is set via the @HoursBack input parameter on the stored proc.

GROUP BY bs.database_name' + @crlf;
SET @StringToExecute += N'UNION ALL' + @crlf + N'SELECT
14 AS CheckId,
100 AS [Priority],
bs.database_name AS [Database Name],
''Backup to NUL device without COPY_ONLY'' AS [Finding],
''The database '' + QUOTENAME(bs.database_name) + '' is not in SIMPLE recovery model and has had '' + CONVERT(VARCHAR(10), COUNT(*)) + '' backups to the NUL device in the last 30 days, the latest one being on ''+
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@BrentOzar BrentOzar Apr 25, 2026

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Let's remove the 30 day reference and just say "backups to the NUL device, the latest one being on" since we're using the @HoursBack parameter.

CONVERT(NVARCHAR(25),MAX(bs.backup_finish_date),120)+''. These backups do not exist and they might mess up your current backup chain.'' AS [Warning]
FROM ' + QUOTENAME(@MSDBName) + '.dbo.backupset AS bs
INNER JOIN ' + QUOTENAME(@MSDBName) + '.dbo.backupmediafamily bmf ON bs.media_set_id = bmf.media_set_id
WHERE UPPER(bmf.physical_device_name)= N''NUL''
AND bs.is_copy_only = 0 AND bs.recovery_model <> N''SIMPLE''
AND bs.backup_finish_date >= DATEADD(DAY, -30, SYSDATETIME())
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@BrentOzar BrentOzar Apr 25, 2026

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Instead of hard-coding 30 days back, let's use the @starttime variable, which is set via the @HoursBack input parameter on the stored proc.

GROUP BY bs.database_name' + @crlf;

IF @Debug = 1
PRINT @StringToExecute;

INSERT #Warnings ( CheckId, Priority, DatabaseName, Finding, Warning )
EXEC sys.sp_executesql @StringToExecute;

RAISERROR('Rules analysis starting on temp tables', 0, 1) WITH NOWAIT;

INSERT #Warnings ( CheckId, Priority, DatabaseName, Finding, Warning )
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