Hard drive requirements

Proper planning of hard drive architecture will help to maintain performance and prevent unnecessary outages. There are performance counters available for monitoring disk usage and disk performance. These can be used to determine if the disk is being heavily used, which might cause slower overall system performance.

Note: To properly plan the hard drive architecture, you should have a basic understanding of RAID (Redundant Array of Independent Disks; see the RAID entry on Wikipedia.

The following are guidelines:

• Separate the operating system (OS) and program files from the data and backups. The following table shows the recommended configuration for each.

  Drive	Used for	Type	RAID
  C:	OS and program files	Internal	1 (mirrored)
  D:	Database files	External	1+0 (or 10), or 0+1 or 5
  E:	Backup	External	RAID is typically not used on a backup drive

• To aid the performance for systems that require a large amount of data be stored for long periods of time or have a high number of MES transactions, you might consider placing the Logs and TempDB on a separate array of disks (RAID 0, 5 or 10).

• For database drives, it is recommended to use RAID 1+0 (sometimes called RAID 10). RAID 5 is also an acceptable approach; however, RAID 10 is recommended as its benefits outweigh the additional costs.

• External storage units are recommended [Storage Area Network (SAN) or Serial Advanced Technology Attachment (SATA)] for everything but the OS. External storage also supports a clustering design if needed in the future.

  Hardware-based RAID arrays (not software) should be used, with all drives being hot-swappable.