I can understand the frustration expressed by Mr Philips (PCW November 2007, Letters), who found that the warranty on his disk drive was invalidated by the action he took to recover the data lost by the disk failure, and by Richard Jones with the failed Nas device (PCW January 2008, Letters).

Unfortunately, it appears that your readers did not appreciate that simple backup and recovery procedures could have lessened the impact of these failures.

There appears to be a misunderstanding among many PC users that Raid technology removes the need for backup. Raid, however, addresses another aspect of data availability - that of continuity of service. This is done by eliminating one of the single points of failure within the storage system.

There are many other such single points of failure in a computer system, which include the power supply, the Raid controller, the path between the storage device and the computer and even the computer itself.

In a business system these risks will be identified, assessed and safeguards put in place. Underpinning all of these will be an effective backup and recovery system. For the home user it is important to protect that all-important data against loss. The most effective way is by introducing some form of backup procedure.

Way back in the days of small hard drives I would save two copies of each document to separate floppy disks. Today, I synchronise data between partitions on a second disk and regularly copy important files to CD or DVD. Yes, I do have a disaster recovery plan.

Please encourage your readers to think carefully about the technologies they choose to secure their data.

Joe Clifford