IT & MCIS

DEFINITION OF STANDARD:
Hardware used to backup and restore critical data residing on file servers.

RATIONALE:
It is recommended that all critical data be stored on file servers rather than individual workstations. In order to keep critical data safe in the event of a disaster, backup hardware and software are installed.

REVIEW CYCLE: Annually
REVISION DATE: May 28 , 2003
EFFECTIVE DATE: December 20, 2000
RESPONSIBLE CONTACT: Help@archive.uky.edu

Recommended Standard(s):
Any server compatible hardware which supports either Direct AudioTape (DAT), 8mm or Digital Linear Tape (DLT) SCSI devices.

Recommended Product(s):
Information Services recommends that all departments use the campus-wide backup server and the CAM backup software available on campus. Although a small monthly charge is required, after the setup of the backup software and items to be backed up, the system is worry-free for the user. In addition, users of the CAM system automatically have the added benefits of remotely stored duplicate tapes and tape/ tape drive format changes managed by the Computing Center.

Justification:
Using DAT, 8mm or DLT backup devices allows for fast, reliable backup and recovery of data.

Technical Considerations:
DAT, 8mm and DLT are SCSI devices. Drive compression and auto-loader capabilities should be taken into consideration. DAT is the most popular solution for low-end systems or non-mission critical file servers with less demanding backup requirements. The prime advantages DLT offers are higher storage capacity, higher data transfer rates, and higher reliability, mainly because the media does not physically touch the head in the drive. Tape drives based on the new Super DLT technology are expected to be capable of storing up to 100GB (uncompressed) on a single cartridge, at transfer speeds up to 40 MBps. The first products based on the new architecture are expected by mid-1999. With all these benefits also comes a steeper price tag. 8mm falls somewhere in between, with higher storage capacities and quicker backup times than DAT tape, but not quite that of DLT. 8mm is cheaper then DLT, but a little more expensive than DAT.

In the near future, departments may need to use a storage area network (SAN) of shared storage devices instead of a discrete tape backup unit at each server. A SAN is a network that contains nothing but a disk or disk array for storing data and serves as a high-speed subnetwork of shared storage devices. These generally utilize a high bandwidth fibre channel connection for transfer of data, but may use a SCSI interface. Using fiber optic cable to connect storage devices, fibre channel supports full-duplex data transfer rates of 100MBps. This architecture makes all storage devices available to all servers on a LAN or WAN. SANs are fairly expensive, and interoperability between vendors currently varies widely. Be sure to verify that all components of your SAN, disk, tape, switches, etc., will all are compatible.

For more information:
See the Computing Centers web site at http://www.uky.edu/ComputingCenter/DataStorage to read more about CAM and see the clients we have available.