Enterprise disk drive

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Enterprise disk drive - is a disk drives marketed for use by the enterprises.

Enterprise computers are typically multiple-user computers with high speed networking running multiple-user applications, or enterprise software. Examples are:

• transaction processing databases
• internet infrastructure (email, webserver, e-commerce)
• file and print software
• scientific computing software
• nearline storage management software

Contents 1 Attributes 2 Drive class 3 Disk enclosures 4 Performance 5 Interfaces

[edit] Attributes

Enterprise disk drives have attributes which distinguish them from the more common type of disk drives found in PCs:^{[citation needed]}

• designed to be run 24 hours per day
• high reliability ratings (measured in mean time to failure (MTTF), typically 1M hours or more
• low annual failure rates (AFR) typically below 0.75%
• interface to RAID controllers or I/O controllers in storage arrays

[edit] Drive class

Enterprise Disk Drives fall into 2 distinct classes

1. drives optimized for performance (typically 15,000 rpm with fast seek times ~2.5 ms) but relatively small capacities ~74GB
2. drives optimized for high capacity (typically 7,200 rpm with slower seek times ~8.9ms) but very large capacities ~750GB.^{[citation needed]}

[edit] Disk enclosures

Main article: Disk enclosure

Enterprise disk drives are usually mounted in enclosures with many disk drives, in these enclosures disk drives are exposed to vibration from fans and other disk drives, so specific technologies^{[citation needed]} for vibration tolerance are often included in Enterprise disk drives.

[edit] Performance

Enterprise disk drives have special firmware for queuing^{[citation needed]} (the organization of lots of simultaneous read and write requests optimized for best performance). Enterprise disk drives often have specific error handling^{[citation needed]} for improved compatibility with RAID controllers.

[edit] Interfaces

The interface connection between the disk drive and the computer may be one of

• Fibre Channel (FC)
• Parallel SCSI (SCSI)
• Serial Attached SCSI (SAS)
• Serial ATA (SATA)

All of these interfaces include industry standards that define interoperability for the electrical connectors, signal levels, power-on protocols, and digital protocols to exchange data and handle errors between computers and disk drives.