SQL Server backup job last 5 days
I use INIT and then my full backups are separate (and include a timestamp to immediately see when they were taken). I can use any method I want to clear out old files (C#, PowerShell, what have you, without having to know the internals of the backup files at all), rather than using xp_delete_file - which is undocumented, unsupported, and could change or be removed in a future release or even a service pack. I don't understand any advantage to stuffing multiple backup files into the same file (which you can't do if you name the file differently using the date anyway). I also don't know why you need to use CONCAT here, but in any case, you can't define an expression in the DDL that way. Why not just:

DECLARE @backup_file VARCHAR(255) = 'D:\Program Files\Microsoft SQL '
  + 'Server\MSSQL11.MSSQLSERVER\MSSQL\Backup\perfMaster_'
  + CONVERT(CHAR(10), GETDATE(), 126) + '.bak';

BACKUP DATABASE perfMaster TO DISK = @backup_file
  WITH INIT, NAME = N'Full Database perfMaster Backup', 
  SKIP, NOREWIND, NOUNLOAD, STATS = 20;


I would also suggest:


using COMPRESSION if your edition supports it.
not storing your backups on the local D:\ drive. If you lose your hard disk, you've lost your database and the backups.