INF: Database Creation and Backup Operations Use Parallelism

SUMMARY

The ALTER DATABASE statement uses parallelism to extend each file on a distinct logical drive. Likewise, the BACKUP DATABASE statement uses a separate thread per logical drive. Although this is a useful performance feature in certain circumstances, it does not mean that creating many logical drives is generally preferred over combining those drives in a RAID array. SQL Server uses asynchronous I/O and can usually leverage all available I/O capacity in a multi-disk RAID array. Combining most available drive spindles to a large RAID array (of the appropriate type) often provides the best performance over the broadest circumstances.